2 doc/src/sgml/ref/psql-ref.sgml
3 PostgreSQL documentation
6 <refentry id="APP-PSQL">
7 <indexterm zone="app-psql">
8 <primary>psql</primary>
12 <refentrytitle><application>psql</application></refentrytitle>
13 <manvolnum>1</manvolnum>
14 <refmiscinfo>Application</refmiscinfo>
18 <refname><application>psql</application></refname>
20 <productname>PostgreSQL</productname> interactive terminal
26 <command>psql</command>
27 <arg rep="repeat"><replaceable class="parameter">option</replaceable></arg>
28 <arg choice="opt"><replaceable class="parameter">dbname</replaceable>
29 <arg choice="opt"><replaceable class="parameter">username</replaceable></arg></arg>
34 <title>Description</title>
37 <application>psql</application> is a terminal-based front-end to
38 <productname>PostgreSQL</productname>. It enables you to type in
39 queries interactively, issue them to
40 <productname>PostgreSQL</productname>, and see the query results.
41 Alternatively, input can be from a file. In addition, it provides a
42 number of meta-commands and various shell-like features to
43 facilitate writing scripts and automating a wide variety of tasks.
47 <refsect1 id="R1-APP-PSQL-3">
48 <title>Options</title>
52 <term><option>-a</></term>
53 <term><option>--echo-all</></term>
56 Print all input lines to standard output as they are read. This is more
57 useful for script processing than interactive mode. This is
58 equivalent to setting the variable <varname>ECHO</varname> to
59 <literal>all</literal>.
65 <term><option>-A</></term>
66 <term><option>--no-align</></term>
69 Switches to unaligned output mode. (The default output mode is
76 <term><option>-c <replaceable class="parameter">command</replaceable></></term>
77 <term><option>--command=<replaceable class="parameter">command</replaceable></></term>
80 Specifies that <application>psql</application> is to execute one
81 command string, <replaceable class="parameter">command</replaceable>,
82 and then exit. This is useful in shell scripts. Start-up files
83 (<filename>psqlrc</filename> and <filename>~/.psqlrc</filename>) are
84 ignored with this option.
87 <replaceable class="parameter">command</replaceable> must be either
88 a command string that is completely parsable by the server (i.e.,
89 it contains no <application>psql</application>-specific features),
90 or a single backslash command. Thus you cannot mix
91 <acronym>SQL</acronym> and <application>psql</application>
92 meta-commands with this option. To achieve that, you could
93 pipe the string into <application>psql</application>, for example:
94 <literal>echo '\x \\ SELECT * FROM foo;' | psql</literal>.
95 (<literal>\\</> is the separator meta-command.)
98 If the command string contains multiple SQL commands, they are
99 processed in a single transaction, unless there are explicit
100 <command>BEGIN</>/<command>COMMIT</> commands included in the
101 string to divide it into multiple transactions. This is
102 different from the behavior when the same string is fed to
103 <application>psql</application>'s standard input. Also, only
104 the result of the last SQL command is returned.
107 Because of these legacy behaviors, putting more than one command in
108 the <option>-c</option> string often has unexpected results. It's
109 better to feed multiple commands to <application>psql</application>'s
110 standard input, either using <application>echo</application> as
111 illustrated above, or via a shell here-document, for example:
123 <term><option>-d <replaceable class="parameter">dbname</replaceable></></term>
124 <term><option>--dbname=<replaceable class="parameter">dbname</replaceable></></term>
127 Specifies the name of the database to connect to. This is
128 equivalent to specifying <replaceable
129 class="parameter">dbname</replaceable> as the first non-option
130 argument on the command line.
133 If this parameter contains an <symbol>=</symbol> sign or starts
134 with a valid <acronym>URI</acronym> prefix
135 (<literal>postgresql://</literal>
136 or <literal>postgres://</literal>), it is treated as a
137 <parameter>conninfo</parameter> string. See <xref
138 linkend="libpq-connstring"> for more information.
144 <term><option>-e</></term>
145 <term><option>--echo-queries</></term>
148 Copy all SQL commands sent to the server to standard output as well.
150 to setting the variable <varname>ECHO</varname> to
151 <literal>queries</literal>.
157 <term><option>-E</></term>
158 <term><option>--echo-hidden</></term>
161 Echo the actual queries generated by <command>\d</command> and other backslash
162 commands. You can use this to study <application>psql</application>'s
163 internal operations. This is equivalent to
164 setting the variable <varname>ECHO_HIDDEN</varname> from within
165 <application>psql</application>.
171 <term><option>-f <replaceable class="parameter">filename</replaceable></></term>
172 <term><option>--file=<replaceable class="parameter">filename</replaceable></></term>
175 Use the file <replaceable class="parameter">filename</replaceable>
176 as the source of commands instead of reading commands interactively.
177 After the file is processed, <application>psql</application>
178 terminates. This is in many ways equivalent to the meta-command
179 <command>\i</command>.
183 If <replaceable>filename</replaceable> is <literal>-</literal>
184 (hyphen), then standard input is read.
188 Using this option is subtly different from writing <literal>psql
190 class="parameter">filename</replaceable></literal>. In general,
191 both will do what you expect, but using <literal>-f</literal>
192 enables some nice features such as error messages with line
193 numbers. There is also a slight chance that using this option will
194 reduce the start-up overhead. On the other hand, the variant using
195 the shell's input redirection is (in theory) guaranteed to yield
196 exactly the same output you would have received had you entered
203 <term><option>-F <replaceable class="parameter">separator</replaceable></></term>
204 <term><option>--field-separator=<replaceable class="parameter">separator</replaceable></></term>
207 Use <replaceable class="parameter">separator</replaceable> as the
208 field separator for unaligned output. This is equivalent to
209 <command>\pset fieldsep</command> or <command>\f</command>.
215 <term><option>-h <replaceable class="parameter">hostname</replaceable></></term>
216 <term><option>--host=<replaceable class="parameter">hostname</replaceable></></term>
219 Specifies the host name of the machine on which the
220 server is running. If the value begins
221 with a slash, it is used as the directory for the Unix-domain
228 <term><option>-H</></term>
229 <term><option>--html</></term>
232 Turn on <acronym>HTML</acronym> tabular output. This is
233 equivalent to <literal>\pset format html</literal> or the
234 <command>\H</command> command.
240 <term><option>-l</></term>
241 <term><option>--list</></term>
244 List all available databases, then exit. Other non-connection
245 options are ignored. This is similar to the meta-command
246 <command>\list</command>.
252 <term><option>-L <replaceable class="parameter">filename</replaceable></></term>
253 <term><option>--log-file=<replaceable class="parameter">filename</replaceable></></term>
256 Write all query output into file <replaceable
257 class="parameter">filename</replaceable>, in addition to the
258 normal output destination.
264 <term><option>-n</></term>
265 <term><option>--no-readline</></term>
268 Do not use <application>readline</application> for line editing and do not use the history.
269 This can be useful to turn off tab expansion when cutting and pasting.
275 <term><option>-o <replaceable class="parameter">filename</replaceable></></term>
276 <term><option>--output=<replaceable class="parameter">filename</replaceable></></term>
279 Put all query output into file <replaceable
280 class="parameter">filename</replaceable>. This is equivalent to
281 the command <command>\o</command>.
287 <term><option>-p <replaceable class="parameter">port</replaceable></></term>
288 <term><option>--port=<replaceable class="parameter">port</replaceable></></term>
291 Specifies the TCP port or the local Unix-domain
292 socket file extension on which the server is listening for
293 connections. Defaults to the value of the <envar>PGPORT</envar>
294 environment variable or, if not set, to the port specified at
295 compile time, usually 5432.
301 <term><option>-P <replaceable class="parameter">assignment</replaceable></></term>
302 <term><option>--pset=<replaceable class="parameter">assignment</replaceable></></term>
305 Specifies printing options, in the style of
306 <command>\pset</command>. Note that here you
307 have to separate name and value with an equal sign instead of a
308 space. For example, to set the output format to <application>LaTeX</application>, you could write
309 <literal>-P format=latex</literal>.
315 <term><option>-q</></term>
316 <term><option>--quiet</></term>
319 Specifies that <application>psql</application> should do its work
320 quietly. By default, it prints welcome messages and various
321 informational output. If this option is used, none of this
322 happens. This is useful with the <option>-c</option> option.
323 Within <application>psql</application> you can also set the
324 <varname>QUIET</varname> variable to achieve the same effect.
330 <term><option>-R <replaceable class="parameter">separator</replaceable></></term>
331 <term><option>--record-separator=<replaceable class="parameter">separator</replaceable></></term>
334 Use <replaceable class="parameter">separator</replaceable> as the
335 record separator for unaligned output. This is equivalent to the
336 <command>\pset recordsep</command> command.
342 <term><option>-s</></term>
343 <term><option>--single-step</></term>
346 Run in single-step mode. That means the user is prompted before
347 each command is sent to the server, with the option to cancel
348 execution as well. Use this to debug scripts.
354 <term><option>-S</></term>
355 <term><option>--single-line</></term>
358 Runs in single-line mode where a newline terminates an SQL command, as a
364 This mode is provided for those who insist on it, but you are not
365 necessarily encouraged to use it. In particular, if you mix
366 <acronym>SQL</acronym> and meta-commands on a line the order of
367 execution might not always be clear to the inexperienced user.
374 <term><option>-t</></term>
375 <term><option>--tuples-only</></term>
378 Turn off printing of column names and result row count footers,
379 etc. This is equivalent to the <command>\t</command> command.
385 <term><option>-T <replaceable class="parameter">table_options</replaceable></></term>
386 <term><option>--table-attr=<replaceable class="parameter">table_options</replaceable></></term>
389 Specifies options to be placed within the
390 <acronym>HTML</acronym> <sgmltag>table</sgmltag> tag. See
391 <command>\pset</command> for details.
397 <term><option>-U <replaceable class="parameter">username</replaceable></></term>
398 <term><option>--username=<replaceable class="parameter">username</replaceable></></term>
401 Connect to the database as the user <replaceable
402 class="parameter">username</replaceable> instead of the default.
403 (You must have permission to do so, of course.)
409 <term><option>-v <replaceable class="parameter">assignment</replaceable></></term>
410 <term><option>--set=<replaceable class="parameter">assignment</replaceable></></term>
411 <term><option>--variable=<replaceable class="parameter">assignment</replaceable></></term>
414 Perform a variable assignment, like the <command>\set</command>
415 meta-command. Note that you must separate name and value, if
416 any, by an equal sign on the command line. To unset a variable,
417 leave off the equal sign. To set a variable with an empty value,
418 use the equal sign but leave off the value. These assignments are
419 done during a very early stage of start-up, so variables reserved
420 for internal purposes might get overwritten later.
426 <term><option>-V</></term>
427 <term><option>--version</></term>
430 Print the <application>psql</application> version and exit.
436 <term><option>-w</></term>
437 <term><option>--no-password</></term>
440 Never issue a password prompt. If the server requires password
441 authentication and a password is not available by other means
442 such as a <filename>.pgpass</filename> file, the connection
443 attempt will fail. This option can be useful in batch jobs and
444 scripts where no user is present to enter a password.
448 Note that this option will remain set for the entire session,
449 and so it affects uses of the meta-command
450 <command>\connect</command> as well as the initial connection attempt.
456 <term><option>-W</></term>
457 <term><option>--password</></term>
460 Force <application>psql</application> to prompt for a
461 password before connecting to a database.
465 This option is never essential, since <application>psql</application>
466 will automatically prompt for a password if the server demands
467 password authentication. However, <application>psql</application>
468 will waste a connection attempt finding out that the server wants a
469 password. In some cases it is worth typing <option>-W</> to avoid
470 the extra connection attempt.
474 Note that this option will remain set for the entire session,
475 and so it affects uses of the meta-command
476 <command>\connect</command> as well as the initial connection attempt.
482 <term><option>-x</></term>
483 <term><option>--expanded</></term>
486 Turn on the expanded table formatting mode. This is equivalent to the
487 <command>\x</command> command.
493 <term><option>-X,</></term>
494 <term><option>--no-psqlrc</></term>
497 Do not read the start-up file (neither the system-wide
498 <filename>psqlrc</filename> file nor the user's
499 <filename>~/.psqlrc</filename> file).
505 <term><option>-z</option></term>
506 <term><option>--field-separator-zero</option></term>
509 Set the field separator for unaligned output to a zero byte.
515 <term><option>-0</option></term>
516 <term><option>--record-separator-zero</option></term>
519 Set the record separator for unaligned output to a zero byte. This is
520 useful for interfacing, for example, with <literal>xargs -0</literal>.
526 <term><option>-1</option></term>
527 <term><option>--single-transaction</option></term>
530 When <application>psql</application> executes a script, adding
531 this option wraps <command>BEGIN</>/<command>COMMIT</> around the
532 script to execute it as a single transaction. This ensures that
533 either all the commands complete successfully, or no changes are
538 If the script itself uses <command>BEGIN</>, <command>COMMIT</>,
539 or <command>ROLLBACK</>, this option will not have the desired
541 Also, if the script contains any command that cannot be executed
542 inside a transaction block, specifying this option will cause that
543 command (and hence the whole transaction) to fail.
549 <term><option>-?</></term>
550 <term><option>--help</></term>
553 Show help about <application>psql</application> command line
564 <title>Exit Status</title>
567 <application>psql</application> returns 0 to the shell if it
568 finished normally, 1 if a fatal error of its own occurs (e.g. out of memory,
569 file not found), 2 if the connection to the server went bad
570 and the session was not interactive, and 3 if an error occurred in a
571 script and the variable <varname>ON_ERROR_STOP</varname> was set.
579 <refsect2 id="R2-APP-PSQL-connecting">
580 <title>Connecting to a Database</title>
583 <application>psql</application> is a regular
584 <productname>PostgreSQL</productname> client application. In order
585 to connect to a database you need to know the name of your target
586 database, the host name and port number of the server, and what user
587 name you want to connect as. <application>psql</application> can be
588 told about those parameters via command line options, namely
589 <option>-d</option>, <option>-h</option>, <option>-p</option>, and
590 <option>-U</option> respectively. If an argument is found that does
591 not belong to any option it will be interpreted as the database name
592 (or the user name, if the database name is already given). Not all
593 of these options are required; there are useful defaults. If you omit the host
594 name, <application>psql</> will connect via a Unix-domain socket
595 to a server on the local host, or via TCP/IP to <literal>localhost</> on
596 machines that don't have Unix-domain sockets. The default port number is
597 determined at compile time.
598 Since the database server uses the same default, you will not have
599 to specify the port in most cases. The default user name is your
600 Unix user name, as is the default database name. Note that you cannot
601 just connect to any database under any user name. Your database
602 administrator should have informed you about your access rights.
606 When the defaults aren't quite right, you can save yourself
607 some typing by setting the environment variables
608 <envar>PGDATABASE</envar>, <envar>PGHOST</envar>,
609 <envar>PGPORT</envar> and/or <envar>PGUSER</envar> to appropriate
610 values. (For additional environment variables, see <xref
611 linkend="libpq-envars">.) It is also convenient to have a
612 <filename>~/.pgpass</> file to avoid regularly having to type in
613 passwords. See <xref linkend="libpq-pgpass"> for more information.
617 An alternative way to specify connection parameters is in a
618 <parameter>conninfo</parameter> string or
619 a <acronym>URI</acronym>, which is used instead of a database
620 name. This mechanism give you very wide control over the
621 connection. For example:
623 $ <userinput>psql "service=myservice sslmode=require"</userinput>
624 $ <userinput>psql postgresql://dbmaster:5433/mydb?sslmode=require</userinput>
626 This way you can also use <acronym>LDAP</acronym> for connection
627 parameter lookup as described in <xref linkend="libpq-ldap">.
628 See <xref linkend="libpq-paramkeywords"> for more information on all the
629 available connection options.
633 If the connection could not be made for any reason (e.g., insufficient
634 privileges, server is not running on the targeted host, etc.),
635 <application>psql</application> will return an error and terminate.
639 If at least one of standard input or standard output are a
640 terminal, then <application>psql</application> sets the client
641 encoding to <quote>auto</quote>, which will detect the
642 appropriate client encoding from the locale settings
643 (<envar>LC_CTYPE</envar> environment variable on Unix systems).
644 If this doesn't work out as expected, the client encoding can be
645 overridden using the environment
646 variable <envar>PGCLIENTENCODING</envar>.
650 <refsect2 id="R2-APP-PSQL-4">
651 <title>Entering SQL Commands</title>
654 In normal operation, <application>psql</application> provides a
655 prompt with the name of the database to which
656 <application>psql</application> is currently connected, followed by
657 the string <literal>=></literal>. For example:
659 $ <userinput>psql testdb</userinput>
661 Type "help" for help.
668 At the prompt, the user can type in <acronym>SQL</acronym> commands.
669 Ordinarily, input lines are sent to the server when a
670 command-terminating semicolon is reached. An end of line does not
671 terminate a command. Thus commands can be spread over several lines for
672 clarity. If the command was sent and executed without error, the results
673 of the command are displayed on the screen.
677 Whenever a command is executed, <application>psql</application> also polls
678 for asynchronous notification events generated by
679 <xref linkend="SQL-LISTEN"> and
680 <xref linkend="SQL-NOTIFY">.
684 <refsect2 id="APP-PSQL-meta-commands">
685 <title>Meta-Commands</title>
688 Anything you enter in <application>psql</application> that begins
689 with an unquoted backslash is a <application>psql</application>
690 meta-command that is processed by <application>psql</application>
691 itself. These commands make
692 <application>psql</application> more useful for administration or
693 scripting. Meta-commands are often called slash or backslash commands.
697 The format of a <application>psql</application> command is the backslash,
698 followed immediately by a command verb, then any arguments. The arguments
699 are separated from the command verb and each other by any number of
700 whitespace characters.
704 To include whitespace in an argument you can quote it with
705 single quotes. To include a single quote in an argument,
706 write two single quotes within single-quoted text.
707 Anything contained in single quotes is
708 furthermore subject to C-like substitutions for
709 <literal>\n</literal> (new line), <literal>\t</literal> (tab),
710 <literal>\b</literal> (backspace), <literal>\r</literal> (carriage return),
711 <literal>\f</literal> (form feed),
712 <literal>\</literal><replaceable>digits</replaceable> (octal), and
713 <literal>\x</literal><replaceable>digits</replaceable> (hexadecimal).
714 A backslash preceding any other character within single-quoted text
715 quotes that single character, whatever it is.
719 Within an argument, text that is enclosed in backquotes
720 (<literal>`</literal>) is taken as a command line that is passed to the
721 shell. The output of the command (with any trailing newline removed)
722 replaces the backquoted text.
726 If an unquoted colon (<literal>:</literal>) followed by a
727 <application>psql</> variable name appears within an argument, it is
728 replaced by the variable's value, as described in <xref
729 linkend="APP-PSQL-interpolation" endterm="APP-PSQL-interpolation-title">.
733 Some commands take an <acronym>SQL</acronym> identifier (such as a
734 table name) as argument. These arguments follow the syntax rules
735 of <acronym>SQL</acronym>: Unquoted letters are forced to
736 lowercase, while double quotes (<literal>"</>) protect letters
737 from case conversion and allow incorporation of whitespace into
738 the identifier. Within double quotes, paired double quotes reduce
739 to a single double quote in the resulting name. For example,
740 <literal>FOO"BAR"BAZ</> is interpreted as <literal>fooBARbaz</>,
741 and <literal>"A weird"" name"</> becomes <literal>A weird"
746 Parsing for arguments stops at the end of the line, or when another
747 unquoted backslash is found. An unquoted backslash
748 is taken as the beginning of a new meta-command. The special
749 sequence <literal>\\</literal> (two backslashes) marks the end of
750 arguments and continues parsing <acronym>SQL</acronym> commands, if
751 any. That way <acronym>SQL</acronym> and
752 <application>psql</application> commands can be freely mixed on a
753 line. But in any case, the arguments of a meta-command cannot
754 continue beyond the end of the line.
758 The following meta-commands are defined:
762 <term><literal>\a</literal></term>
765 If the current table output format is unaligned, it is switched to aligned.
766 If it is not unaligned, it is set to unaligned. This command is
767 kept for backwards compatibility. See <command>\pset</command> for a
768 more general solution.
774 <term><literal>\c</literal> or <literal>\connect</literal> <literal>[ <replaceable class="parameter">dbname</replaceable> [ <replaceable class="parameter">username</replaceable> ] [ <replaceable class="parameter">host</replaceable> ] [ <replaceable class="parameter">port</replaceable> ] ]</literal></term>
777 Establishes a new connection to a <productname>PostgreSQL</>
778 server. If the new connection is successfully made, the
779 previous connection is closed. If any of <replaceable
780 class="parameter">dbname</replaceable>, <replaceable
781 class="parameter">username</replaceable>, <replaceable
782 class="parameter">host</replaceable> or <replaceable
783 class="parameter">port</replaceable> are omitted or specified
784 as <literal>-</literal>, the value of that parameter from the
785 previous connection is used. If there is no previous
786 connection, the <application>libpq</application> default for
787 the parameter's value is used.
791 If the connection attempt failed (wrong user name, access
792 denied, etc.), the previous connection will only be kept if
793 <application>psql</application> is in interactive mode. When
794 executing a non-interactive script, processing will
795 immediately stop with an error. This distinction was chosen as
796 a user convenience against typos on the one hand, and a safety
797 mechanism that scripts are not accidentally acting on the
798 wrong database on the other hand.
804 <term><literal>\C [ <replaceable class="parameter">title</replaceable> ]</literal></term>
807 Sets the title of any tables being printed as the result of a
808 query or unset any such title. This command is equivalent to
809 <literal>\pset title <replaceable
810 class="parameter">title</replaceable></literal>. (The name of
811 this command derives from <quote>caption</quote>, as it was
812 previously only used to set the caption in an
813 <acronym>HTML</acronym> table.)
819 <term><literal>\cd [ <replaceable>directory</replaceable> ]</literal></term>
822 Changes the current working directory to
823 <replaceable>directory</replaceable>. Without argument, changes
824 to the current user's home directory.
829 To print your current working directory, use <literal>\! pwd</literal>.
836 <term><literal>\conninfo</literal></term>
839 Outputs information about the current database connection.
844 <varlistentry id="APP-PSQL-meta-commands-copy">
845 <term><literal>\copy { <replaceable class="parameter">table</replaceable> [ ( <replaceable class="parameter">column_list</replaceable> ) ] | ( <replaceable class="parameter">query</replaceable> ) }
846 { <literal>from</literal> | <literal>to</literal> }
847 { <replaceable class="parameter">'filename'</replaceable> | program <replaceable class="parameter">'command'</replaceable> | stdin | stdout | pstdin | pstdout }
848 [ [ with ] ( <replaceable class="parameter">option</replaceable> [, ...] ) ]</literal></term>
852 Performs a frontend (client) copy. This is an operation that
853 runs an <acronym>SQL</acronym> <xref linkend="SQL-COPY">
854 command, but instead of the server
855 reading or writing the specified file,
856 <application>psql</application> reads or writes the file and
857 routes the data between the server and the local file system.
858 This means that file accessibility and privileges are those of
859 the local user, not the server, and no SQL superuser
860 privileges are required.
864 When <literal>program</> is specified,
865 <replaceable class="parameter">command</replaceable> is
866 executed by <application>psql</application> and the data from
867 or to <replaceable class="parameter">command</replaceable> is
868 routed between the server and the client.
869 This means that the execution privileges are those of
870 the local user, not the server, and no SQL superuser
871 privileges are required.
874 <para><literal>\copy ... from stdin | to stdout</literal>
875 reads/writes based on the command input and output respectively.
876 All rows are read from the same source that issued the command,
877 continuing until <literal>\.</literal> is read or the stream
878 reaches <acronym>EOF</>. Output is sent to the same place as
879 command output. To read/write from
880 <application>psql</application>'s standard input or output, use
881 <literal>pstdin</> or <literal>pstdout</>. This option is useful
882 for populating tables in-line within a SQL script file.
886 The syntax of the command is similar to that of the
887 <acronym>SQL</acronym> <xref linkend="sql-copy">
889 <replaceable class="parameter">option</replaceable>
890 must indicate one of the options of the
891 <acronym>SQL</acronym> <xref linkend="sql-copy"> command.
892 Note that, because of this,
893 special parsing rules apply to the <command>\copy</command>
894 command. In particular, the variable substitution rules and
895 backslash escapes do not apply.
900 This operation is not as efficient as the <acronym>SQL</acronym>
901 <command>COPY</command> command because all data must pass
902 through the client/server connection. For large
903 amounts of data the <acronym>SQL</acronym> command might be preferable.
911 <term><literal>\copyright</literal></term>
914 Shows the copyright and distribution terms of
915 <productname>PostgreSQL</productname>.
921 <term><literal>\d[S+] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
925 For each relation (table, view, index, sequence, or foreign table)
926 or composite type matching the
927 <replaceable class="parameter">pattern</replaceable>, show all
928 columns, their types, the tablespace (if not the default) and any
929 special attributes such as <literal>NOT NULL</literal> or defaults.
930 Associated indexes, constraints, rules, and triggers are
931 also shown. For foreign tables, the associated foreign
932 server is shown as well.
933 (<quote>Matching the pattern</> is defined in
934 <xref linkend="APP-PSQL-patterns" endterm="APP-PSQL-patterns-title">
939 For some types of relation, <literal>\d</> shows additional information
940 for each column: column values for sequences, indexed expression for
941 indexes and foreign data wrapper options for foreign tables.
945 The command form <literal>\d+</literal> is identical, except that
946 more information is displayed: any comments associated with the
947 columns of the table are shown, as is the presence of OIDs in the
948 table, the view definition if the relation is a view.
952 By default, only user-created objects are shown; supply a
953 pattern or the <literal>S</literal> modifier to include system
959 If <command>\d</command> is used without a
960 <replaceable class="parameter">pattern</replaceable> argument, it is
961 equivalent to <command>\dtvsE</command> which will show a list of
962 all visible tables, views, sequences and foreign tables.
963 This is purely a convenience measure.
970 <term><literal>\da[S] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
974 Lists aggregate functions, together with their
975 return type and the data types they operate on. If <replaceable
976 class="parameter">pattern</replaceable>
977 is specified, only aggregates whose names match the pattern are shown.
978 By default, only user-created objects are shown; supply a
979 pattern or the <literal>S</literal> modifier to include system
987 <term><literal>\db[+] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
991 Lists tablespaces. If <replaceable
992 class="parameter">pattern</replaceable>
993 is specified, only tablespaces whose names match the pattern are shown.
994 If <literal>+</literal> is appended to the command name, each object
995 is listed with its associated permissions.
1002 <term><literal>\dc[S+] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
1005 Lists conversions between character-set encodings.
1006 If <replaceable class="parameter">pattern</replaceable>
1007 is specified, only conversions whose names match the pattern are
1009 By default, only user-created objects are shown; supply a
1010 pattern or the <literal>S</literal> modifier to include system
1012 If <literal>+</literal> is appended to the command name, each object
1013 is listed with its associated description.
1020 <term><literal>\dC[+] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
1024 If <replaceable class="parameter">pattern</replaceable>
1025 is specified, only casts whose source or target types match the
1027 If <literal>+</literal> is appended to the command name, each object
1028 is listed with its associated description.
1035 <term><literal>\dd[S] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
1038 Shows the descriptions of objects of type <literal>constraint</>,
1039 <literal>operator class</>, <literal>operator family</>,
1040 <literal>rule</>, and <literal>trigger</>. All
1041 other comments may be viewed by the respective backslash commands for
1045 <para><literal>\dd</literal> displays descriptions for objects matching the
1046 <replaceable class="parameter">pattern</replaceable>, or of visible
1047 objects of the appropriate type if no argument is given. But in either
1048 case, only objects that have a description are listed.
1049 By default, only user-created objects are shown; supply a
1050 pattern or the <literal>S</literal> modifier to include system
1055 Descriptions for objects can be created with the <xref
1056 linkend="sql-comment">
1057 <acronym>SQL</acronym> command.
1064 <term><literal>\ddp [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
1067 Lists default access privilege settings. An entry is shown for
1068 each role (and schema, if applicable) for which the default
1069 privilege settings have been changed from the built-in defaults.
1070 If <replaceable class="parameter">pattern</replaceable> is
1071 specified, only entries whose role name or schema name matches
1072 the pattern are listed.
1076 The <xref linkend="sql-alterdefaultprivileges"> command is used to set
1077 default access privileges. The meaning of the
1078 privilege display is explained under
1079 <xref linkend="sql-grant">.
1086 <term><literal>\dD[S+] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
1089 Lists domains. If <replaceable
1090 class="parameter">pattern</replaceable>
1091 is specified, only domains whose names match the pattern are shown.
1092 By default, only user-created objects are shown; supply a
1093 pattern or the <literal>S</literal> modifier to include system
1095 If <literal>+</literal> is appended to the command name, each object
1096 is listed with its associated permissions and description.
1103 <term><literal>\dE[S+] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
1104 <term><literal>\di[S+] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
1105 <term><literal>\dm[S+] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
1106 <term><literal>\ds[S+] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
1107 <term><literal>\dt[S+] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
1108 <term><literal>\dv[S+] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
1112 In this group of commands, the letters <literal>E</literal>,
1113 <literal>i</literal>, <literal>m</literal>, <literal>s</literal>,
1114 <literal>t</literal>, and <literal>v</literal>
1115 stand for foreign table, index, materialized view, sequence, table, and view,
1117 You can specify any or all of
1118 these letters, in any order, to obtain a listing of objects
1119 of these types. For example, <literal>\dit</> lists indexes
1120 and tables. If <literal>+</literal> is
1121 appended to the command name, each object is listed with its
1122 physical size on disk and its associated description, if any.
1123 If <replaceable class="parameter">pattern</replaceable> is
1124 specified, only objects whose names match the pattern are listed.
1125 By default, only user-created objects are shown; supply a
1126 pattern or the <literal>S</literal> modifier to include system
1134 <term><literal>\des[+] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
1137 Lists foreign servers (mnemonic: <quote>external
1139 If <replaceable class="parameter">pattern</replaceable> is
1140 specified, only those servers whose name matches the pattern
1141 are listed. If the form <literal>\des+</literal> is used, a
1142 full description of each server is shown, including the
1143 server's ACL, type, version, options, and description.
1150 <term><literal>\det[+] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
1153 Lists foreign tables (mnemonic: <quote>external tables</quote>).
1154 If <replaceable class="parameter">pattern</replaceable> is
1155 specified, only entries whose table name or schema name matches
1156 the pattern are listed. If the form <literal>\det+</literal>
1157 is used, generic options and the foreign table description
1165 <term><literal>\deu[+] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
1168 Lists user mappings (mnemonic: <quote>external
1170 If <replaceable class="parameter">pattern</replaceable> is
1171 specified, only those mappings whose user names match the
1172 pattern are listed. If the form <literal>\deu+</literal> is
1173 used, additional information about each mapping is shown.
1178 <literal>\deu+</literal> might also display the user name and
1179 password of the remote user, so care should be taken not to
1188 <term><literal>\dew[+] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
1191 Lists foreign-data wrappers (mnemonic: <quote>external
1193 If <replaceable class="parameter">pattern</replaceable> is
1194 specified, only those foreign-data wrappers whose name matches
1195 the pattern are listed. If the form <literal>\dew+</literal>
1196 is used, the ACL, options, and description of the foreign-data
1197 wrapper are also shown.
1204 <term><literal>\df[antwS+] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
1208 Lists functions, together with their arguments, return types, and
1209 function types, which are classified as <quote>agg</> (aggregate),
1210 <quote>normal</>, <quote>trigger</>, or <quote>window</>.
1211 To display only functions
1212 of specific type(s), add the corresponding letters <literal>a</>,
1213 <literal>n</>, <literal>t</>, or <literal>w</> to the command.
1215 class="parameter">pattern</replaceable> is specified, only
1216 functions whose names match the pattern are shown.
1217 By default, only user-created
1218 objects are shown; supply a pattern or the <literal>S</literal>
1219 modifier to include system objects.
1220 If the form <literal>\df+</literal> is used, additional information
1221 about each function is shown, including security classification,
1222 volatility, owner, language, source code and description.
1227 To look up functions taking arguments or returning values of a specific
1228 type, use your pager's search capability to scroll through the
1229 <literal>\df</> output.
1237 <term><literal>\dF[+] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
1240 Lists text search configurations.
1241 If <replaceable class="parameter">pattern</replaceable> is specified,
1242 only configurations whose names match the pattern are shown.
1243 If the form <literal>\dF+</literal> is used, a full description of
1244 each configuration is shown, including the underlying text search
1245 parser and the dictionary list for each parser token type.
1251 <term><literal>\dFd[+] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
1254 Lists text search dictionaries.
1255 If <replaceable class="parameter">pattern</replaceable> is specified,
1256 only dictionaries whose names match the pattern are shown.
1257 If the form <literal>\dFd+</literal> is used, additional information
1258 is shown about each selected dictionary, including the underlying
1259 text search template and the option values.
1265 <term><literal>\dFp[+] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
1268 Lists text search parsers.
1269 If <replaceable class="parameter">pattern</replaceable> is specified,
1270 only parsers whose names match the pattern are shown.
1271 If the form <literal>\dFp+</literal> is used, a full description of
1272 each parser is shown, including the underlying functions and the
1273 list of recognized token types.
1279 <term><literal>\dFt[+] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
1282 Lists text search templates.
1283 If <replaceable class="parameter">pattern</replaceable> is specified,
1284 only templates whose names match the pattern are shown.
1285 If the form <literal>\dFt+</literal> is used, additional information
1286 is shown about each template, including the underlying function names.
1293 <term><literal>\dg[+] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
1296 Lists database roles.
1297 (Since the concepts of <quote>users</> and <quote>groups</> have been
1298 unified into <quote>roles</>, this command is now equivalent to
1299 <literal>\du</literal>.)
1300 If <replaceable class="parameter">pattern</replaceable> is specified,
1301 only those roles whose names match the pattern are listed.
1302 If the form <literal>\dg+</literal> is used, additional information
1303 is shown about each role; currently this adds the comment for each
1311 <term><literal>\dl</literal></term>
1314 This is an alias for <command>\lo_list</command>, which shows a
1315 list of large objects.
1321 <term><literal>\dL[S+] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
1324 Lists procedural languages. If <replaceable
1325 class="parameter">pattern</replaceable>
1326 is specified, only languages whose names match the pattern are listed.
1327 By default, only user-created languages
1328 are shown; supply the <literal>S</literal> modifier to include system
1329 objects. If <literal>+</literal> is appended to the command name, each
1330 language is listed with its call handler, validator, access privileges,
1331 and whether it is a system object.
1338 <term><literal>\dn[S+] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
1342 Lists schemas (namespaces). If <replaceable
1343 class="parameter">pattern</replaceable>
1344 is specified, only schemas whose names match the pattern are listed.
1345 By default, only user-created objects are shown; supply a
1346 pattern or the <literal>S</literal> modifier to include system objects.
1347 If <literal>+</literal> is appended to the command name, each object
1348 is listed with its associated permissions and description, if any.
1355 <term><literal>\do[S+] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
1358 Lists operators with their operand and result types.
1359 If <replaceable class="parameter">pattern</replaceable> is
1360 specified, only operators whose names match the pattern are listed.
1361 By default, only user-created objects are shown; supply a
1362 pattern or the <literal>S</literal> modifier to include system
1364 If <literal>+</literal> is appended to the command name,
1365 additional information about each operator is shown, currently just
1366 the name of the underlying function.
1373 <term><literal>\dO[S+] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
1377 If <replaceable class="parameter">pattern</replaceable> is
1378 specified, only collations whose names match the pattern are
1379 listed. By default, only user-created objects are shown;
1380 supply a pattern or the <literal>S</literal> modifier to
1381 include system objects. If <literal>+</literal> is appended
1382 to the command name, each collation is listed with its associated
1383 description, if any.
1384 Note that only collations usable with the current database's encoding
1385 are shown, so the results may vary in different databases of the
1393 <term><literal>\dp [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
1396 Lists tables, views and sequences with their
1397 associated access privileges.
1398 If <replaceable class="parameter">pattern</replaceable> is
1399 specified, only tables, views and sequences whose names match the
1404 The <xref linkend="sql-grant"> and
1405 <xref linkend="sql-revoke">
1406 commands are used to set access privileges. The meaning of the
1407 privilege display is explained under
1408 <xref linkend="sql-grant">.
1414 <term><literal>\drds [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">role-pattern</replaceable></link> [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">database-pattern</replaceable></link> ] ]</literal></term>
1417 Lists defined configuration settings. These settings can be
1418 role-specific, database-specific, or both.
1419 <replaceable>role-pattern</replaceable> and
1420 <replaceable>database-pattern</replaceable> are used to select
1421 specific roles and databases to list, respectively. If omitted, or if
1422 <literal>*</> is specified, all settings are listed, including those
1423 not role-specific or database-specific, respectively.
1427 The <xref linkend="sql-alterrole"> and
1428 <xref linkend="sql-alterdatabase">
1429 commands are used to define per-role and per-database configuration
1436 <term><literal>\dT[S+] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
1440 If <replaceable class="parameter">pattern</replaceable> is
1441 specified, only types whose names match the pattern are listed.
1442 If <literal>+</literal> is appended to the command name, each type is
1443 listed with its internal name and size, its allowed values
1444 if it is an <type>enum</> type, and its associated permissions.
1445 By default, only user-created objects are shown; supply a
1446 pattern or the <literal>S</literal> modifier to include system
1453 <term><literal>\du[+] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
1456 Lists database roles.
1457 (Since the concepts of <quote>users</> and <quote>groups</> have been
1458 unified into <quote>roles</>, this command is now equivalent to
1459 <literal>\dg</literal>.)
1460 If <replaceable class="parameter">pattern</replaceable> is specified,
1461 only those roles whose names match the pattern are listed.
1462 If the form <literal>\du+</literal> is used, additional information
1463 is shown about each role; currently this adds the comment for each
1470 <term><literal>\dx[+] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
1473 Lists installed extensions.
1474 If <replaceable class="parameter">pattern</replaceable>
1475 is specified, only those extensions whose names match the pattern
1477 If the form <literal>\dx+</literal> is used, all the objects belonging
1478 to each matching extension are listed.
1484 <term><literal>\dy[+] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
1487 Lists event triggers.
1488 If <replaceable class="parameter">pattern</replaceable>
1489 is specified, only those event triggers whose names match the pattern
1491 If <literal>+</literal> is appended to the command name, each object
1492 is listed with its associated description.
1498 <term><literal>\e</literal> or <literal>\edit</> <literal> <optional> <replaceable class="parameter">filename</> </optional> <optional> <replaceable class="parameter">line_number</> </optional> </literal></term>
1502 If <replaceable class="parameter">filename</replaceable> is
1503 specified, the file is edited; after the editor exits, its
1504 content is copied back to the query buffer. If no <replaceable
1505 class="parameter">filename</replaceable> is given, the current query
1506 buffer is copied to a temporary file which is then edited in the same
1511 The new query buffer is then re-parsed according to the normal
1512 rules of <application>psql</application>, where the whole buffer
1513 is treated as a single line. (Thus you cannot make scripts this
1514 way. Use <command>\i</command> for that.) This means that
1515 if the query ends with (or contains) a semicolon, it is
1516 immediately executed. Otherwise it will merely wait in the
1517 query buffer; type semicolon or <literal>\g</> to send it, or
1518 <literal>\r</> to cancel.
1522 If a line number is specified, <application>psql</application> will
1523 position the cursor on the specified line of the file or query buffer.
1524 Note that if a single all-digits argument is given,
1525 <application>psql</application> assumes it is a line number,
1531 See under <xref linkend="app-psql-environment"
1532 endterm="app-psql-environment-title"> for how to configure and
1533 customize your editor.
1540 <term><literal>\echo <replaceable class="parameter">text</replaceable> [ ... ]</literal></term>
1543 Prints the arguments to the standard output, separated by one
1544 space and followed by a newline. This can be useful to
1545 intersperse information in the output of scripts. For example:
1547 => <userinput>\echo `date`</userinput>
1548 Tue Oct 26 21:40:57 CEST 1999
1550 If the first argument is an unquoted <literal>-n</literal> the trailing
1551 newline is not written.
1556 If you use the <command>\o</command> command to redirect your
1557 query output you might wish to use <command>\qecho</command>
1558 instead of this command.
1565 <term><literal>\ef <optional> <replaceable class="parameter">function_description</> <optional> <replaceable class="parameter">line_number</> </optional> </optional> </literal></term>
1569 This command fetches and edits the definition of the named function,
1570 in the form of a <command>CREATE OR REPLACE FUNCTION</> command.
1571 Editing is done in the same way as for <literal>\edit</>.
1572 After the editor exits, the updated command waits in the query buffer;
1573 type semicolon or <literal>\g</> to send it, or <literal>\r</>
1578 The target function can be specified by name alone, or by name
1579 and arguments, for example <literal>foo(integer, text)</>.
1580 The argument types must be given if there is more
1581 than one function of the same name.
1585 If no function is specified, a blank <command>CREATE FUNCTION</>
1586 template is presented for editing.
1590 If a line number is specified, <application>psql</application> will
1591 position the cursor on the specified line of the function body.
1592 (Note that the function body typically does not begin on the first
1598 See under <xref linkend="app-psql-environment"
1599 endterm="app-psql-environment-title"> for how to configure and
1600 customize your editor.
1608 <term><literal>\encoding [ <replaceable class="parameter">encoding</replaceable> ]</literal></term>
1612 Sets the client character set encoding. Without an argument, this command
1613 shows the current encoding.
1620 <term><literal>\f [ <replaceable class="parameter">string</replaceable> ]</literal></term>
1624 Sets the field separator for unaligned query output. The default
1625 is the vertical bar (<literal>|</literal>). See also
1626 <command>\pset</command> for a generic way of setting output
1634 <term><literal>\g</literal> [ { <replaceable class="parameter">filename</replaceable> | <literal>|</literal><replaceable class="parameter">command</replaceable> } ]</term>
1638 Sends the current query input buffer to the server and
1639 optionally stores the query's output in <replaceable
1640 class="parameter">filename</replaceable> or pipes the output
1641 into a separate Unix shell executing <replaceable
1642 class="parameter">command</replaceable>. The file or command is
1643 written to only if the query successfully returns zero or more tuples,
1644 not if the query fails or is a non-data-returning SQL command.
1647 A bare <literal>\g</literal> is essentially equivalent to a semicolon.
1648 A <literal>\g</literal> with argument is a <quote>one-shot</quote>
1649 alternative to the <command>\o</command> command.
1655 <term><literal>\gset</literal> [ <replaceable class="parameter">prefix</replaceable> ]</term>
1659 Sends the current query input buffer to the server and stores the
1660 query's output into <application>psql</> variables (see <xref
1661 linkend="APP-PSQL-variables" endterm="APP-PSQL-variables-title">).
1662 The query to be executed must return exactly one row. Each column of
1663 the row is stored into a separate variable, named the same as the
1664 column. For example:
1666 => <userinput>SELECT 'hello' AS var1, 10 AS var2</userinput>
1667 -> <userinput>\gset</userinput>
1668 => <userinput>\echo :var1 :var2</userinput>
1673 If you specify a <replaceable class="parameter">prefix</replaceable>,
1674 that string is prepended to the query's column names to create the
1675 variable names to use:
1677 => <userinput>SELECT 'hello' AS var1, 10 AS var2</userinput>
1678 -> <userinput>\gset result_</userinput>
1679 => <userinput>\echo :result_var1 :result_var2</userinput>
1684 If a column result is NULL, the corresponding variable is unset
1685 rather than being set.
1688 If the query fails or does not return one row,
1689 no variables are changed.
1695 <term><literal>\h</literal> or <literal>\help</literal> <literal>[ <replaceable class="parameter">command</replaceable> ]</literal></term>
1698 Gives syntax help on the specified <acronym>SQL</acronym>
1699 command. If <replaceable class="parameter">command</replaceable>
1700 is not specified, then <application>psql</application> will list
1701 all the commands for which syntax help is available. If
1702 <replaceable class="parameter">command</replaceable> is an
1703 asterisk (<literal>*</literal>), then syntax help on all
1704 <acronym>SQL</acronym> commands is shown.
1709 To simplify typing, commands that consists of several words do
1710 not have to be quoted. Thus it is fine to type <userinput>\help
1711 alter table</userinput>.
1719 <term><literal>\H</literal></term>
1722 Turns on <acronym>HTML</acronym> query output format. If the
1723 <acronym>HTML</acronym> format is already on, it is switched
1724 back to the default aligned text format. This command is for
1725 compatibility and convenience, but see <command>\pset</command>
1726 about setting other output options.
1733 <term><literal>\i <replaceable class="parameter">filename</replaceable></literal></term>
1736 Reads input from the file <replaceable
1737 class="parameter">filename</replaceable> and executes it as
1738 though it had been typed on the keyboard.
1742 If you want to see the lines on the screen as they are read you
1743 must set the variable <varname>ECHO</varname> to
1744 <literal>all</literal>.
1752 <term><literal>\ir <replaceable class="parameter">filename</replaceable></literal></term>
1755 The <literal>\ir</> command is similar to <literal>\i</>, but resolves
1756 relative file names differently. When executing in interactive mode,
1757 the two commands behave identically. However, when invoked from a
1758 script, <literal>\ir</literal> interprets file names relative to the
1759 directory in which the script is located, rather than the current
1767 <term><literal>\l[+]</literal> or <literal>\list[+] [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
1770 List the databases in the server and show their names, owners,
1771 character set encodings, and access privileges.
1772 If <replaceable class="parameter">pattern</replaceable> is specified,
1773 only databases whose names match the pattern are listed.
1774 If <literal>+</literal> is appended to the command name, database
1775 sizes, default tablespaces, and descriptions are also displayed.
1776 (Size information is only available for databases that the current
1777 user can connect to.)
1784 <term><literal>\lo_export <replaceable class="parameter">loid</replaceable> <replaceable class="parameter">filename</replaceable></literal></term>
1788 Reads the large object with <acronym>OID</acronym> <replaceable
1789 class="parameter">loid</replaceable> from the database and
1790 writes it to <replaceable
1791 class="parameter">filename</replaceable>. Note that this is
1792 subtly different from the server function
1793 <function>lo_export</function>, which acts with the permissions
1794 of the user that the database server runs as and on the server's
1799 Use <command>\lo_list</command> to find out the large object's
1800 <acronym>OID</acronym>.
1808 <term><literal>\lo_import <replaceable class="parameter">filename</replaceable> [ <replaceable class="parameter">comment</replaceable> ]</literal></term>
1812 Stores the file into a <productname>PostgreSQL</productname>
1813 large object. Optionally, it associates the given
1814 comment with the object. Example:
1816 foo=> <userinput>\lo_import '/home/peter/pictures/photo.xcf' 'a picture of me'</userinput>
1819 The response indicates that the large object received object
1820 ID 152801, which can be used to access the newly-created large
1821 object in the future. For the sake of readability, it is
1822 recommended to always associate a human-readable comment with
1823 every object. Both OIDs and comments can be viewed with the
1824 <command>\lo_list</command> command.
1828 Note that this command is subtly different from the server-side
1829 <function>lo_import</function> because it acts as the local user
1830 on the local file system, rather than the server's user and file
1837 <term><literal>\lo_list</literal></term>
1840 Shows a list of all <productname>PostgreSQL</productname>
1841 large objects currently stored in the database,
1842 along with any comments provided for them.
1848 <term><literal>\lo_unlink <replaceable class="parameter">loid</replaceable></literal></term>
1852 Deletes the large object with <acronym>OID</acronym>
1853 <replaceable class="parameter">loid</replaceable> from the
1859 Use <command>\lo_list</command> to find out the large object's
1860 <acronym>OID</acronym>.
1868 <term><literal>\o</literal> [ {<replaceable class="parameter">filename</replaceable> | <literal>|</literal><replaceable class="parameter">command</replaceable>} ]</term>
1872 Saves future query results to the file <replaceable
1873 class="parameter">filename</replaceable> or pipes future results
1874 into a separate Unix shell to execute <replaceable
1875 class="parameter">command</replaceable>. If no arguments are
1876 specified, the query output will be reset to the standard output.
1879 <para><quote>Query results</quote> includes all tables, command
1880 responses, and notices obtained from the database server, as
1881 well as output of various backslash commands that query the
1882 database (such as <command>\d</command>), but not error
1888 To intersperse text output in between query results, use
1889 <command>\qecho</command>.
1897 <term><literal>\p</literal></term>
1900 Print the current query buffer to the standard output.
1906 <term><literal>\password [ <replaceable class="parameter">username</replaceable> ]</literal></term>
1909 Changes the password of the specified user (by default, the current
1910 user). This command prompts for the new password, encrypts it, and
1911 sends it to the server as an <command>ALTER ROLE</> command. This
1912 makes sure that the new password does not appear in cleartext in the
1913 command history, the server log, or elsewhere.
1919 <term><literal>\prompt [ <replaceable class="parameter">text</replaceable> ] <replaceable class="parameter">name</replaceable></literal></term>
1922 Prompts the user to supply text, which is assigned to the variable
1923 <replaceable class="parameter">name</>.
1924 An optional prompt string, <replaceable
1925 class="parameter">text</>, can be specified. (For multiword
1926 prompts, surround the text with single quotes.)
1930 By default, <literal>\prompt</> uses the terminal for input and
1931 output. However, if the <option>-f</> command line switch was
1932 used, <literal>\prompt</> uses standard input and standard output.
1938 <term><literal>\pset <replaceable class="parameter">option</replaceable> [ <replaceable class="parameter">value</replaceable> ]</literal></term>
1942 This command sets options affecting the output of query result tables.
1943 <replaceable class="parameter">option</replaceable>
1944 indicates which option is to be set. The semantics of
1945 <replaceable class="parameter">value</replaceable> vary depending
1946 on the selected option. For some options, omitting <replaceable
1947 class="parameter">value</replaceable> causes the option to be toggled
1948 or unset, as described under the particular option. If no such
1949 behavior is mentioned, then omitting
1950 <replaceable class="parameter">value</replaceable> just results in
1951 the current setting being displayed.
1955 Adjustable printing options are:
1958 <term><literal>border</literal></term>
1961 The <replaceable class="parameter">value</replaceable> must be a
1962 number. In general, the higher
1963 the number the more borders and lines the tables will have,
1964 but this depends on the particular format. In
1965 <acronym>HTML</acronym> format, this will translate directly
1966 into the <literal>border=...</literal> attribute; in the
1967 other formats only values 0 (no border), 1 (internal dividing lines),
1968 and 2 (table frame) make sense.
1969 <literal>latex</literal> and <literal>latex-longtable</literal>
1970 also support a <literal>border</literal> value of 3 which adds
1971 a dividing line between each row.
1977 <term><literal>columns</literal></term>
1980 Sets the target width for the <literal>wrapped</> format, and also
1981 the width limit for determining whether output is wide enough to
1982 require the pager or switch to the vertical display in expanded auto
1984 Zero (the default) causes the target width to be controlled by the
1985 environment variable <envar>COLUMNS</>, or the detected screen width
1986 if <envar>COLUMNS</> is not set.
1987 In addition, if <literal>columns</> is zero then the
1988 <literal>wrapped</> format only affects screen output.
1989 If <literal>columns</> is nonzero then file and pipe output is
1990 wrapped to that width as well.
1996 <term><literal>expanded</literal> (or <literal>x</literal>)</term>
1999 If <replaceable class="parameter">value</replaceable> is specified it
2000 must be either <literal>on</literal> or <literal>off</literal>, which
2001 will enable or disable expanded mode, or <literal>auto</literal>.
2002 If <replaceable class="parameter">value</replaceable> is omitted the
2003 command toggles between the on and off settings. When expanded mode
2004 is enabled, query results are displayed in two columns, with the
2005 column name on the left and the data on the right. This mode is
2006 useful if the data wouldn't fit on the screen in the
2007 normal <quote>horizontal</quote> mode. In the auto setting, the
2008 expanded mode is used whenever the query output is wider than the
2009 screen, otherwise the regular mode is used. The auto setting is only
2010 effective in the aligned and wrapped formats. In other formats, it
2011 always behaves as if the expanded mode is off.
2017 <term><literal>fieldsep</literal></term>
2020 Specifies the field separator to be used in unaligned output
2021 format. That way one can create, for example, tab- or
2022 comma-separated output, which other programs might prefer. To
2023 set a tab as field separator, type <literal>\pset fieldsep
2024 '\t'</literal>. The default field separator is
2025 <literal>'|'</literal> (a vertical bar).
2031 <term><literal>fieldsep_zero</literal></term>
2034 Sets the field separator to use in unaligned output format to a zero
2041 <term><literal>footer</literal></term>
2044 If <replaceable class="parameter">value</replaceable> is specified
2045 it must be either <literal>on</literal> or <literal>off</literal>
2046 which will enable or disable display of the table footer
2047 (the <literal>(<replaceable>n</> rows)</literal> count).
2048 If <replaceable class="parameter">value</replaceable> is omitted the
2049 command toggles footer display on or off.
2055 <term><literal>format</literal></term>
2058 Sets the output format to one of <literal>unaligned</literal>,
2059 <literal>aligned</literal>, <literal>wrapped</literal>,
2060 <literal>html</literal>,
2061 <literal>latex</literal> (uses <literal>tabular</literal>),
2062 <literal>latex-longtable</literal>, or
2063 <literal>troff-ms</literal>.
2064 Unique abbreviations are allowed. (That would mean one letter
2068 <para><literal>unaligned</> format writes all columns of a row on one
2069 line, separated by the currently active field separator. This
2070 is useful for creating output that might be intended to be read
2071 in by other programs (for example, tab-separated or comma-separated
2075 <para><literal>aligned</literal> format is the standard, human-readable,
2076 nicely formatted text output; this is the default.
2079 <para><literal>wrapped</> format is like <literal>aligned</> but wraps
2080 wide data values across lines to make the output fit in the target
2081 column width. The target width is determined as described under
2082 the <literal>columns</> option. Note that <application>psql</> will
2083 not attempt to wrap column header titles; therefore,
2084 <literal>wrapped</> format behaves the same as <literal>aligned</>
2085 if the total width needed for column headers exceeds the target.
2089 The <literal>html</>, <literal>latex</>,
2090 <literal>latex-longtable</literal>, and <literal>troff-ms</>
2091 formats put out tables that are intended to
2092 be included in documents using the respective mark-up
2093 language. They are not complete documents! This might not be
2094 necessary in <acronym>HTML</acronym>, but in
2095 <application>LaTeX</application> you must have a complete
2096 document wrapper. <literal>latex-longtable</literal>
2097 also requires the <application>LaTeX</application>
2098 <literal>longtable</literal> and <literal>booktabs</> packages.
2104 <term><literal>linestyle</literal></term>
2107 Sets the border line drawing style to one
2108 of <literal>ascii</literal>, <literal>old-ascii</literal>
2109 or <literal>unicode</literal>.
2110 Unique abbreviations are allowed. (That would mean one
2112 The default setting is <literal>ascii</>.
2113 This option only affects the <literal>aligned</> and
2114 <literal>wrapped</> output formats.
2117 <para><literal>ascii</literal> style uses plain <acronym>ASCII</acronym>
2118 characters. Newlines in data are shown using
2119 a <literal>+</literal> symbol in the right-hand margin.
2120 When the <literal>wrapped</literal> format wraps data from
2121 one line to the next without a newline character, a dot
2122 (<literal>.</>) is shown in the right-hand margin of the first line,
2123 and again in the left-hand margin of the following line.
2126 <para><literal>old-ascii</literal> style uses plain <acronym>ASCII</>
2127 characters, using the formatting style used
2128 in <productname>PostgreSQL</productname> 8.4 and earlier.
2129 Newlines in data are shown using a <literal>:</literal>
2130 symbol in place of the left-hand column separator.
2131 When the data is wrapped from one line
2132 to the next without a newline character, a <literal>;</>
2133 symbol is used in place of the left-hand column separator.
2136 <para><literal>unicode</literal> style uses Unicode box-drawing characters.
2137 Newlines in data are shown using a carriage return symbol
2138 in the right-hand margin. When the data is wrapped from one line
2139 to the next without a newline character, an ellipsis symbol
2140 is shown in the right-hand margin of the first line, and
2141 again in the left-hand margin of the following line.
2145 When the <literal>border</> setting is greater than zero,
2146 this option also determines the characters
2147 with which the border lines are drawn.
2148 Plain <acronym>ASCII</acronym> characters work everywhere, but
2149 Unicode characters look nicer on displays that recognize them.
2155 <term><literal>null</literal></term>
2158 Sets the string to be printed in place of a null value.
2159 The default is to print nothing, which can easily be mistaken for
2160 an empty string. For example, one might prefer <literal>\pset null
2167 <term><literal>numericlocale</literal></term>
2170 If <replaceable class="parameter">value</replaceable> is specified
2171 it must be either <literal>on</literal> or <literal>off</literal>
2172 which will enable or disable display of a locale-specific character
2173 to separate groups of digits to the left of the decimal marker.
2174 If <replaceable class="parameter">value</replaceable> is omitted the
2175 command toggles between regular and locale-specific numeric output.
2181 <term><literal>pager</literal></term>
2184 Controls use of a pager program for query and <application>psql</>
2185 help output. If the environment variable <envar>PAGER</envar>
2186 is set, the output is piped to the specified program.
2187 Otherwise a platform-dependent default (such as
2188 <filename>more</filename>) is used.
2192 When the <literal>pager</> option is <literal>off</>, the pager
2193 program is not used. When the <literal>pager</> option is
2194 <literal>on</>, the pager is used when appropriate, i.e., when the
2195 output is to a terminal and will not fit on the screen.
2196 The <literal>pager</> option can also be set to <literal>always</>,
2197 which causes the pager to be used for all terminal output regardless
2198 of whether it fits on the screen. <literal>\pset pager</>
2199 without a <replaceable class="parameter">value</replaceable>
2200 toggles pager use on and off.
2206 <term><literal>recordsep</literal></term>
2209 Specifies the record (line) separator to use in unaligned
2210 output format. The default is a newline character.
2216 <term><literal>recordsep_zero</literal></term>
2219 Sets the record separator to use in unaligned output format to a zero
2226 <term><literal>tableattr</literal> (or <literal>T</literal>)</term>
2229 In <acronym>HTML</acronym> format, this specifies attributes
2230 to be placed inside the <sgmltag>table</sgmltag> tag. This
2231 could for example be <literal>cellpadding</literal> or
2232 <literal>bgcolor</literal>. Note that you probably don't want
2233 to specify <literal>border</literal> here, as that is already
2234 taken care of by <literal>\pset border</literal>.
2236 <replaceable class="parameter">value</replaceable> is given,
2237 the table attributes are unset.
2240 In <literal>latex-longtable</literal> format, this controls
2241 the proportional width of each column containing a left-aligned
2242 data type. It is specified as a whitespace-separated list of values,
2243 e.g. <literal>'0.2 0.2 0.6'</>. Unspecified output columns
2244 use the last specified value.
2250 <term><literal>title</literal></term>
2253 Sets the table title for any subsequently printed tables. This
2254 can be used to give your output descriptive tags. If no
2255 <replaceable class="parameter">value</replaceable> is given,
2262 <term><literal>tuples_only</literal> (or <literal>t</literal>)</term>
2265 If <replaceable class="parameter">value</replaceable> is specified
2266 it must be either <literal>on</literal> or <literal>off</literal>
2267 which will enable or disable tuples-only mode.
2268 If <replaceable class="parameter">value</replaceable> is omitted the
2269 command toggles between regular and tuples-only output.
2270 Regular output includes extra information such
2271 as column headers, titles, and various footers. In tuples-only
2272 mode, only actual table data is shown.
2280 Illustrations of how these different formats look can be seen in
2281 the <xref linkend="APP-PSQL-examples"
2282 endterm="APP-PSQL-examples-title"> section.
2287 There are various shortcut commands for <command>\pset</command>. See
2288 <command>\a</command>, <command>\C</command>, <command>\H</command>,
2289 <command>\t</command>, <command>\T</command>, and <command>\x</command>.
2294 <command>\pset</command> without any arguments displays the current status
2295 of all printing options.
2303 <term><literal>\q</literal> or <literal>\quit</literal></term>
2306 Quits the <application>psql</application> program.
2307 In a script file, only execution of that script is terminated.
2314 <term><literal>\qecho <replaceable class="parameter">text</replaceable> [ ... ] </literal></term>
2317 This command is identical to <command>\echo</command> except
2318 that the output will be written to the query output channel, as
2319 set by <command>\o</command>.
2326 <term><literal>\r</literal></term>
2329 Resets (clears) the query buffer.
2336 <term><literal>\s [ <replaceable class="parameter">filename</replaceable> ]</literal></term>
2339 Print or save the command line history to <replaceable
2340 class="parameter">filename</replaceable>. If <replaceable
2341 class="parameter">filename</replaceable> is omitted, the history
2342 is written to the standard output. This option is only available
2343 if <application>psql</application> is configured to use the
2344 <acronym>GNU</acronym> <application>Readline</application> library.
2351 <term><literal>\set [ <replaceable class="parameter">name</replaceable> [ <replaceable class="parameter">value</replaceable> [ ... ] ] ]</literal></term>
2355 Sets the <application>psql</> variable <replaceable
2356 class="parameter">name</replaceable> to <replaceable
2357 class="parameter">value</replaceable>, or if more than one value
2358 is given, to the concatenation of all of them. If only one
2359 argument is given, the variable is set with an empty value. To
2360 unset a variable, use the <command>\unset</command> command.
2363 <para><command>\set</> without any arguments displays the names and values
2364 of all currently-set <application>psql</> variables.
2368 Valid variable names can contain letters, digits, and
2369 underscores. See the section <xref
2370 linkend="APP-PSQL-variables"
2371 endterm="APP-PSQL-variables-title"> below for details.
2372 Variable names are case-sensitive.
2376 Although you are welcome to set any variable to anything you
2377 want, <application>psql</application> treats several variables
2378 as special. They are documented in the section about variables.
2383 This command is unrelated to the <acronym>SQL</acronym>
2384 command <xref linkend="SQL-SET">.
2392 <term><literal>\setenv [ <replaceable class="parameter">name</replaceable> [ <replaceable class="parameter">value</replaceable> ] ]</literal></term>
2396 Sets the environment variable <replaceable
2397 class="parameter">name</replaceable> to <replaceable
2398 class="parameter">value</replaceable>, or if the
2399 <replaceable class="parameter">value</replaceable> is
2400 not supplied, unsets the environment variable. Example:
2402 testdb=> <userinput>\setenv PAGER less</userinput>
2403 testdb=> <userinput>\setenv LESS -imx4F</userinput>
2404 </programlisting></para>
2409 <term><literal>\sf[+] <replaceable class="parameter">function_description</> </literal></term>
2413 This command fetches and shows the definition of the named function,
2414 in the form of a <command>CREATE OR REPLACE FUNCTION</> command.
2415 The definition is printed to the current query output channel,
2416 as set by <command>\o</command>.
2420 The target function can be specified by name alone, or by name
2421 and arguments, for example <literal>foo(integer, text)</>.
2422 The argument types must be given if there is more
2423 than one function of the same name.
2427 If <literal>+</literal> is appended to the command name, then the
2428 output lines are numbered, with the first line of the function body
2436 <term><literal>\t</literal></term>
2439 Toggles the display of output column name headings and row count
2440 footer. This command is equivalent to <literal>\pset
2441 tuples_only</literal> and is provided for convenience.
2448 <term><literal>\T <replaceable class="parameter">table_options</replaceable></literal></term>
2451 Specifies attributes to be placed within the
2452 <sgmltag>table</sgmltag> tag in <acronym>HTML</acronym>
2453 output format. This command is equivalent to <literal>\pset
2454 tableattr <replaceable
2455 class="parameter">table_options</replaceable></literal>.
2462 <term><literal>\timing [ <replaceable class="parameter">on</replaceable> | <replaceable class="parameter">off</replaceable> ]</literal></term>
2465 Without parameter, toggles a display of how long each SQL statement
2466 takes, in milliseconds. With parameter, sets same.
2473 <term><literal>\unset <replaceable class="parameter">name</replaceable></literal></term>
2477 Unsets (deletes) the <application>psql</> variable <replaceable
2478 class="parameter">name</replaceable>.
2485 <term><literal>\w</literal> <replaceable class="parameter">filename</replaceable></term>
2486 <term><literal>\w</literal> <literal>|</><replaceable class="parameter">command</replaceable></term>
2489 Outputs the current query buffer to the file <replaceable
2490 class="parameter">filename</replaceable> or pipes it to the Unix
2491 command <replaceable class="parameter">command</replaceable>.
2498 <term><literal>\watch [ <replaceable class="parameter">seconds</replaceable> ]</literal></term>
2501 Repeatedly execute the current query buffer (like <literal>\g</>)
2502 until interrupted or the query fails. Wait the specified number of
2503 seconds (default 2) between executions.
2510 <term><literal>\x [ <replaceable class="parameter">on</replaceable> | <replaceable class="parameter">off</replaceable> | <replaceable class="parameter">auto</replaceable> ]</literal></term>
2513 Sets or toggles expanded table formatting mode. As such it is equivalent to
2514 <literal>\pset expanded</literal>.
2521 <term><literal>\z [ <link linkend="APP-PSQL-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
2524 Lists tables, views and sequences with their
2525 associated access privileges.
2526 If a <replaceable class="parameter">pattern</replaceable> is
2527 specified, only tables, views and sequences whose names match the
2532 This is an alias for <command>\dp</command> (<quote>display
2533 privileges</quote>).
2540 <term><literal>\! [ <replaceable class="parameter">command</replaceable> ]</literal></term>
2543 Escapes to a separate Unix shell or executes the Unix command
2544 <replaceable class="parameter">command</replaceable>. The
2545 arguments are not further interpreted; the shell will see them
2546 as-is. In particular, the variable substitution rules and
2547 backslash escapes do not apply.
2554 <term><literal>\?</literal></term>
2557 Shows help information about the backslash commands.
2565 <refsect3 id="APP-PSQL-patterns">
2566 <title id="APP-PSQL-patterns-title">Patterns</title>
2569 <primary>patterns</primary>
2570 <secondary>in psql and pg_dump</secondary>
2574 The various <literal>\d</> commands accept a <replaceable
2575 class="parameter">pattern</replaceable> parameter to specify the
2576 object name(s) to be displayed. In the simplest case, a pattern
2577 is just the exact name of the object. The characters within a
2578 pattern are normally folded to lower case, just as in SQL names;
2579 for example, <literal>\dt FOO</> will display the table named
2580 <literal>foo</>. As in SQL names, placing double quotes around
2581 a pattern stops folding to lower case. Should you need to include
2582 an actual double quote character in a pattern, write it as a pair
2583 of double quotes within a double-quote sequence; again this is in
2584 accord with the rules for SQL quoted identifiers. For example,
2585 <literal>\dt "FOO""BAR"</> will display the table named
2586 <literal>FOO"BAR</> (not <literal>foo"bar</>). Unlike the normal
2587 rules for SQL names, you can put double quotes around just part
2588 of a pattern, for instance <literal>\dt FOO"FOO"BAR</> will display
2589 the table named <literal>fooFOObar</>.
2593 Whenever the <replaceable class="parameter">pattern</replaceable> parameter
2594 is omitted completely, the <literal>\d</> commands display all objects
2595 that are visible in the current schema search path — this is
2596 equivalent to using <literal>*</> as the pattern.
2597 (An object is said to be <firstterm>visible</> if its
2598 containing schema is in the search path and no object of the same
2599 kind and name appears earlier in the search path. This is equivalent to the
2600 statement that the object can be referenced by name without explicit
2601 schema qualification.)
2602 To see all objects in the database regardless of visibility,
2603 use <literal>*.*</> as the pattern.
2607 Within a pattern, <literal>*</> matches any sequence of characters
2608 (including no characters) and <literal>?</> matches any single character.
2609 (This notation is comparable to Unix shell file name patterns.)
2610 For example, <literal>\dt int*</> displays tables whose names
2611 begin with <literal>int</>. But within double quotes, <literal>*</>
2612 and <literal>?</> lose these special meanings and are just matched
2617 A pattern that contains a dot (<literal>.</>) is interpreted as a schema
2618 name pattern followed by an object name pattern. For example,
2619 <literal>\dt foo*.*bar*</> displays all tables whose table name
2620 includes <literal>bar</> that are in schemas whose schema name
2621 starts with <literal>foo</>. When no dot appears, then the pattern
2622 matches only objects that are visible in the current schema search path.
2623 Again, a dot within double quotes loses its special meaning and is matched
2628 Advanced users can use regular-expression notations such as character
2629 classes, for example <literal>[0-9]</> to match any digit. All regular
2630 expression special characters work as specified in
2631 <xref linkend="functions-posix-regexp">, except for <literal>.</> which
2632 is taken as a separator as mentioned above, <literal>*</> which is
2633 translated to the regular-expression notation <literal>.*</>,
2634 <literal>?</> which is translated to <literal>.</>, and
2635 <literal>$</> which is matched literally. You can emulate
2636 these pattern characters at need by writing
2637 <literal>?</> for <literal>.</>,
2638 <literal>(<replaceable class="parameter">R</replaceable>+|)</literal> for
2639 <literal><replaceable class="parameter">R</replaceable>*</literal>, or
2640 <literal>(<replaceable class="parameter">R</replaceable>|)</literal> for
2641 <literal><replaceable class="parameter">R</replaceable>?</literal>.
2642 <literal>$</> is not needed as a regular-expression character since
2643 the pattern must match the whole name, unlike the usual
2644 interpretation of regular expressions (in other words, <literal>$</>
2645 is automatically appended to your pattern). Write <literal>*</> at the
2646 beginning and/or end if you don't wish the pattern to be anchored.
2647 Note that within double quotes, all regular expression special characters
2648 lose their special meanings and are matched literally. Also, the regular
2649 expression special characters are matched literally in operator name
2650 patterns (i.e., the argument of <literal>\do</>).
2656 <title>Advanced Features</title>
2658 <refsect3 id="APP-PSQL-variables">
2659 <title id="APP-PSQL-variables-title">Variables</title>
2662 <application>psql</application> provides variable substitution
2663 features similar to common Unix command shells.
2664 Variables are simply name/value pairs, where the value
2665 can be any string of any length. The name must consist of letters
2666 (including non-Latin letters), digits, and underscores.
2670 To set a variable, use the <application>psql</application> meta-command
2671 <command>\set</command>. For example,
2673 testdb=> <userinput>\set foo bar</userinput>
2675 sets the variable <literal>foo</literal> to the value
2676 <literal>bar</literal>. To retrieve the content of the variable, precede
2677 the name with a colon, for example:
2679 testdb=> <userinput>\echo :foo</userinput>
2682 This works in both regular SQL commands and meta-commands; there is
2683 more detail in <xref linkend="APP-PSQL-interpolation"
2684 endterm="APP-PSQL-interpolation-title">, below.
2688 If you call <command>\set</command> without a second argument, the
2689 variable is set, with an empty string as value. To unset (i.e., delete)
2690 a variable, use the command <command>\unset</command>. To show the
2691 values of all variables, call <command>\set</command> without any argument.
2696 The arguments of <command>\set</command> are subject to the same
2697 substitution rules as with other commands. Thus you can construct
2698 interesting references such as <literal>\set :foo
2699 'something'</literal> and get <quote>soft links</quote> or
2700 <quote>variable variables</quote> of <productname>Perl</productname>
2701 or <productname><acronym>PHP</acronym></productname> fame,
2702 respectively. Unfortunately (or fortunately?), there is no way to do
2703 anything useful with these constructs. On the other hand,
2704 <literal>\set bar :foo</literal> is a perfectly valid way to copy a
2710 A number of these variables are treated specially
2711 by <application>psql</application>. They represent certain option
2712 settings that can be changed at run time by altering the value of
2713 the variable, or in some cases represent changeable state of
2714 <application>psql</application>. Although
2715 you can use these variables for other purposes, this is not
2716 recommended, as the program behavior might grow really strange
2717 really quickly. By convention, all specially treated variables' names
2718 consist of all upper-case ASCII letters (and possibly digits and
2719 underscores). To ensure maximum compatibility in the future, avoid
2720 using such variable names for your own purposes. A list of all specially
2721 treated variables follows.
2727 <primary>autocommit</primary>
2728 <secondary>psql</secondary>
2730 <term><varname>AUTOCOMMIT</varname></term>
2733 When <literal>on</> (the default), each SQL command is automatically
2734 committed upon successful completion. To postpone commit in this
2735 mode, you must enter a <command>BEGIN</> or <command>START
2736 TRANSACTION</> SQL command. When <literal>off</> or unset, SQL
2737 commands are not committed until you explicitly issue
2738 <command>COMMIT</> or <command>END</>. The autocommit-off
2739 mode works by issuing an implicit <command>BEGIN</> for you, just
2740 before any command that is not already in a transaction block and
2741 is not itself a <command>BEGIN</> or other transaction-control
2742 command, nor a command that cannot be executed inside a transaction
2743 block (such as <command>VACUUM</>).
2748 In autocommit-off mode, you must explicitly abandon any failed
2749 transaction by entering <command>ABORT</> or <command>ROLLBACK</>.
2750 Also keep in mind that if you exit the session
2751 without committing, your work will be lost.
2757 The autocommit-on mode is <productname>PostgreSQL</>'s traditional
2758 behavior, but autocommit-off is closer to the SQL spec. If you
2759 prefer autocommit-off, you might wish to set it in the system-wide
2760 <filename>psqlrc</filename> file or your
2761 <filename>~/.psqlrc</filename> file.
2768 <term><varname>COMP_KEYWORD_CASE</varname></term>
2771 Determines which letter case to use when completing an SQL key word.
2772 If set to <literal>lower</literal> or <literal>upper</literal>, the
2773 completed word will be in lower or upper case, respectively. If set
2774 to <literal>preserve-lower</literal>
2775 or <literal>preserve-upper</literal> (the default), the completed word
2776 will be in the case of the word already entered, but words being
2777 completed without anything entered will be in lower or upper case,
2784 <term><varname>DBNAME</varname></term>
2787 The name of the database you are currently connected to. This is
2788 set every time you connect to a database (including program
2789 start-up), but can be unset.
2795 <term><varname>ECHO</varname></term>
2798 If set to <literal>all</literal>, all lines
2799 entered from the keyboard or from a script are written to the standard output
2800 before they are parsed or executed. To select this behavior on program
2801 start-up, use the switch <option>-a</option>. If set to
2802 <literal>queries</literal>,
2803 <application>psql</application> merely prints all queries as
2804 they are sent to the server. The switch for this is
2805 <option>-e</option>.
2811 <term><varname>ECHO_HIDDEN</varname></term>
2814 When this variable is set and a backslash command queries the
2815 database, the query is first shown. This way you can study the
2816 <productname>PostgreSQL</productname> internals and provide
2817 similar functionality in your own programs. (To select this behavior
2818 on program start-up, use the switch <option>-E</option>.) If you set
2819 the variable to the value <literal>noexec</literal>, the queries are
2820 just shown but are not actually sent to the server and executed.
2826 <term><varname>ENCODING</varname></term>
2829 The current client character set encoding.
2835 <term><varname>FETCH_COUNT</varname></term>
2838 If this variable is set to an integer value > 0,
2839 the results of <command>SELECT</command> queries are fetched
2840 and displayed in groups of that many rows, rather than the
2841 default behavior of collecting the entire result set before
2842 display. Therefore only a
2843 limited amount of memory is used, regardless of the size of
2844 the result set. Settings of 100 to 1000 are commonly used
2845 when enabling this feature.
2846 Keep in mind that when using this feature, a query might
2847 fail after having already displayed some rows.
2851 Although you can use any output format with this feature,
2852 the default <literal>aligned</> format tends to look bad
2853 because each group of <varname>FETCH_COUNT</varname> rows
2854 will be formatted separately, leading to varying column
2855 widths across the row groups. The other output formats work better.
2862 <term><varname>HISTCONTROL</varname></term>
2865 If this variable is set to <literal>ignorespace</literal>,
2866 lines which begin with a space are not entered into the history
2867 list. If set to a value of <literal>ignoredups</literal>, lines
2868 matching the previous history line are not entered. A value of
2869 <literal>ignoreboth</literal> combines the two options. If
2870 unset, or if set to any other value than those above, all lines
2871 read in interactive mode are saved on the history list.
2875 This feature was shamelessly plagiarized from
2876 <application>Bash</application>.
2883 <term><varname>HISTFILE</varname></term>
2886 The file name that will be used to store the history list. The default
2887 value is <filename>~/.psql_history</filename>. For example, putting:
2889 \set HISTFILE ~/.psql_history- :DBNAME
2891 in <filename>~/.psqlrc</filename> will cause
2892 <application>psql</application> to maintain a separate history for
2897 This feature was shamelessly plagiarized from
2898 <application>Bash</application>.
2905 <term><varname>HISTSIZE</varname></term>
2908 The number of commands to store in the command history. The
2909 default value is 500.
2913 This feature was shamelessly plagiarized from
2914 <application>Bash</application>.
2921 <term><varname>HOST</varname></term>
2924 The database server host you are currently connected to. This is
2925 set every time you connect to a database (including program
2926 start-up), but can be unset.
2932 <term><varname>IGNOREEOF</varname></term>
2935 If unset, sending an <acronym>EOF</> character (usually
2936 <keycombo action="simul"><keycap>Control</><keycap>D</></>)
2937 to an interactive session of <application>psql</application>
2938 will terminate the application. If set to a numeric value,
2939 that many <acronym>EOF</> characters are ignored before the
2940 application terminates. If the variable is set but has no
2941 numeric value, the default is 10.
2945 This feature was shamelessly plagiarized from
2946 <application>Bash</application>.
2953 <term><varname>LASTOID</varname></term>
2956 The value of the last affected OID, as returned from an
2957 <command>INSERT</command> or <command>\lo_import</command>
2958 command. This variable is only guaranteed to be valid until
2959 after the result of the next <acronym>SQL</acronym> command has
2967 <primary>rollback</primary>
2968 <secondary>psql</secondary>
2970 <term><varname>ON_ERROR_ROLLBACK</varname></term>
2973 When <literal>on</>, if a statement in a transaction block
2974 generates an error, the error is ignored and the transaction
2975 continues. When <literal>interactive</>, such errors are only
2976 ignored in interactive sessions, and not when reading script
2977 files. When <literal>off</> (the default), a statement in a
2978 transaction block that generates an error aborts the entire
2979 transaction. The on_error_rollback-on mode works by issuing an
2980 implicit <command>SAVEPOINT</> for you, just before each command
2981 that is in a transaction block, and rolls back to the savepoint
2988 <term><varname>ON_ERROR_STOP</varname></term>
2991 By default, command processing continues after an error. When this
2992 variable is set, it will instead stop immediately. In interactive mode,
2993 <application>psql</application> will return to the command prompt;
2994 otherwise, <application>psql</application> will exit, returning
2995 error code 3 to distinguish this case from fatal error
2996 conditions, which are reported using error code 1. In either case,
2997 any currently running scripts (the top-level script, if any, and any
2998 other scripts which it may have in invoked) will be terminated
2999 immediately. If the top-level command string contained multiple SQL
3000 commands, processing will stop with the current command.
3006 <term><varname>PORT</varname></term>
3009 The database server port to which you are currently connected.
3010 This is set every time you connect to a database (including
3011 program start-up), but can be unset.
3017 <term><varname>PROMPT1</varname></term>
3018 <term><varname>PROMPT2</varname></term>
3019 <term><varname>PROMPT3</varname></term>
3022 These specify what the prompts <application>psql</application>
3023 issues should look like. See <xref
3024 linkend="APP-PSQL-prompting"
3025 endterm="APP-PSQL-prompting-title"> below.
3031 <term><varname>QUIET</varname></term>
3034 This variable is equivalent to the command line option
3035 <option>-q</option>. It is probably not too useful in
3042 <term><varname>SINGLELINE</varname></term>
3045 This variable is equivalent to the command line option
3046 <option>-S</option>.
3052 <term><varname>SINGLESTEP</varname></term>
3055 This variable is equivalent to the command line option
3056 <option>-s</option>.
3062 <term><varname>USER</varname></term>
3065 The database user you are currently connected as. This is set
3066 every time you connect to a database (including program
3067 start-up), but can be unset.
3073 <term><varname>VERBOSITY</varname></term>
3076 This variable can be set to the values <literal>default</>,
3077 <literal>verbose</>, or <literal>terse</> to control the verbosity
3087 <refsect3 id="APP-PSQL-interpolation">
3088 <title id="APP-PSQL-interpolation-title"><acronym>SQL</acronym> Interpolation</title>
3091 A key feature of <application>psql</application>
3092 variables is that you can substitute (<quote>interpolate</quote>)
3093 them into regular <acronym>SQL</acronym> statements, as well as the
3094 arguments of meta-commands. Furthermore,
3095 <application>psql</application> provides facilities for
3096 ensuring that variable values used as SQL literals and identifiers are
3097 properly quoted. The syntax for interpolating a value without
3098 any quoting is to prepend the variable name with a colon
3099 (<literal>:</literal>). For example,
3101 testdb=> <userinput>\set foo 'my_table'</userinput>
3102 testdb=> <userinput>SELECT * FROM :foo;</userinput>
3104 would query the table <literal>my_table</literal>. Note that this
3105 may be unsafe: the value of the variable is copied literally, so it can
3106 contain unbalanced quotes, or even backslash commands. You must make sure
3107 that it makes sense where you put it.
3111 When a value is to be used as an SQL literal or identifier, it is
3112 safest to arrange for it to be quoted. To quote the value of
3113 a variable as an SQL literal, write a colon followed by the variable
3114 name in single quotes. To quote the value as an SQL identifier, write
3115 a colon followed by the variable name in double quotes.
3116 These constructs deal correctly with quotes and other special
3117 characters embedded within the variable value.
3118 The previous example would be more safely written this way:
3120 testdb=> <userinput>\set foo 'my_table'</userinput>
3121 testdb=> <userinput>SELECT * FROM :"foo";</userinput>
3126 Variable interpolation will not be performed within quoted
3127 <acronym>SQL</acronym> literals and identifiers. Therefore, a
3128 construction such as <literal>':foo'</> doesn't work to produce a quoted
3129 literal from a variable's value (and it would be unsafe if it did work,
3130 since it wouldn't correctly handle quotes embedded in the value).
3134 One example use of this mechanism is to
3135 copy the contents of a file into a table column.
3136 First load the file into a variable and then interpolate the variable's
3137 value as a quoted string:
3139 testdb=> <userinput>\set content `cat my_file.txt`</userinput>
3140 testdb=> <userinput>INSERT INTO my_table VALUES (:'content');</userinput>
3142 (Note that this still won't work if <filename>my_file.txt</filename> contains NUL bytes.
3143 <application>psql</application> does not support embedded NUL bytes in variable values.)
3147 Since colons can legally appear in SQL commands, an apparent attempt
3148 at interpolation (that is, <literal>:name</literal>,
3149 <literal>:'name'</literal>, or <literal>:"name"</literal>) is not
3150 replaced unless the named variable is currently set. In any case, you
3151 can escape a colon with a backslash to protect it from substitution.
3155 The colon syntax for variables is standard <acronym>SQL</acronym> for
3156 embedded query languages, such as <application>ECPG</application>.
3157 The colon syntaxes for array slices and type casts are
3158 <productname>PostgreSQL</productname> extensions, which can sometimes
3159 conflict with the standard usage. The colon-quote syntax for escaping a
3160 variable's value as an SQL literal or identifier is a
3161 <application>psql</application> extension.
3166 <refsect3 id="APP-PSQL-prompting">
3167 <title id="APP-PSQL-prompting-title">Prompting</title>
3170 The prompts <application>psql</application> issues can be customized
3171 to your preference. The three variables <varname>PROMPT1</varname>,
3172 <varname>PROMPT2</varname>, and <varname>PROMPT3</varname> contain strings
3173 and special escape sequences that describe the appearance of the
3174 prompt. Prompt 1 is the normal prompt that is issued when
3175 <application>psql</application> requests a new command. Prompt 2 is
3176 issued when more input is expected during command input because the
3177 command was not terminated with a semicolon or a quote was not closed.
3178 Prompt 3 is issued when you run an <acronym>SQL</acronym>
3179 <command>COPY</command> command and you are expected to type in the
3180 row values on the terminal.
3184 The value of the selected prompt variable is printed literally,
3185 except where a percent sign (<literal>%</literal>) is encountered.
3186 Depending on the next character, certain other text is substituted
3187 instead. Defined substitutions are:
3191 <term><literal>%M</literal></term>
3194 The full host name (with domain name) of the database server,
3195 or <literal>[local]</literal> if the connection is over a Unix
3197 <literal>[local:<replaceable>/dir/name</replaceable>]</literal>,
3198 if the Unix domain socket is not at the compiled in default
3205 <term><literal>%m</literal></term>
3208 The host name of the database server, truncated at the
3209 first dot, or <literal>[local]</literal> if the connection is
3210 over a Unix domain socket.
3216 <term><literal>%></literal></term>
3217 <listitem><para>The port number at which the database server is listening.</para></listitem>
3221 <term><literal>%n</literal></term>
3224 The database session user name. (The expansion of this
3225 value might change during a database session as the result
3226 of the command <command>SET SESSION
3227 AUTHORIZATION</command>.)
3233 <term><literal>%/</literal></term>
3234 <listitem><para>The name of the current database.</para></listitem>
3238 <term><literal>%~</literal></term>
3239 <listitem><para>Like <literal>%/</literal>, but the output is <literal>~</literal>
3240 (tilde) if the database is your default database.</para></listitem>
3244 <term><literal>%#</literal></term>
3247 If the session user is a database superuser, then a
3248 <literal>#</literal>, otherwise a <literal>></literal>.
3249 (The expansion of this value might change during a database
3250 session as the result of the command <command>SET SESSION
3251 AUTHORIZATION</command>.)
3257 <term><literal>%R</literal></term>
3260 In prompt 1 normally <literal>=</literal>, but <literal>^</literal> if
3261 in single-line mode, and <literal>!</literal> if the session is
3262 disconnected from the database (which can happen if
3263 <command>\connect</command> fails). In prompt 2 the sequence is
3264 replaced by <literal>-</literal>, <literal>*</literal>, a single quote,
3265 a double quote, or a dollar sign, depending on whether
3266 <application>psql</application> expects more input because the
3267 command wasn't terminated yet, because you are inside a
3268 <literal>/* ... */</literal> comment, or because you are inside
3269 a quoted or dollar-escaped string. In prompt 3 the sequence doesn't
3276 <term><literal>%x</literal></term>
3279 Transaction status: an empty string when not in a transaction
3280 block, or <literal>*</> when in a transaction block, or
3281 <literal>!</> when in a failed transaction block, or <literal>?</>
3282 when the transaction state is indeterminate (for example, because
3283 there is no connection).
3289 <term><literal>%</literal><replaceable class="parameter">digits</replaceable></term>
3292 The character with the indicated octal code is substituted.
3298 <term><literal>%:</literal><replaceable class="parameter">name</replaceable><literal>:</literal></term>
3301 The value of the <application>psql</application> variable
3302 <replaceable class="parameter">name</replaceable>. See the
3303 section <xref linkend="APP-PSQL-variables"
3304 endterm="APP-PSQL-variables-title"> for details.
3310 <term><literal>%`</literal><replaceable class="parameter">command</replaceable><literal>`</literal></term>
3313 The output of <replaceable
3314 class="parameter">command</replaceable>, similar to ordinary
3315 <quote>back-tick</quote> substitution.
3321 <term><literal>%[</literal> ... <literal>%]</literal></term>
3324 Prompts can contain terminal control characters which, for
3325 example, change the color, background, or style of the prompt
3326 text, or change the title of the terminal window. In order for
3327 the line editing features of <application>Readline</application> to work properly, these
3328 non-printing control characters must be designated as invisible
3329 by surrounding them with <literal>%[</literal> and
3330 <literal>%]</literal>. Multiple pairs of these can occur within
3331 the prompt. For example:
3333 testdb=> \set PROMPT1 '%[%033[1;33;40m%]%n@%/%R%[%033[0m%]%# '
3335 results in a boldfaced (<literal>1;</literal>) yellow-on-black
3336 (<literal>33;40</literal>) prompt on VT100-compatible, color-capable
3344 To insert a percent sign into your prompt, write
3345 <literal>%%</literal>. The default prompts are
3346 <literal>'%/%R%# '</literal> for prompts 1 and 2, and
3347 <literal>'>> '</literal> for prompt 3.
3352 This feature was shamelessly plagiarized from
3353 <application>tcsh</application>.
3360 <title>Command-Line Editing</title>
3363 <application>psql</application> supports the <application>Readline</application>
3364 library for convenient line editing and retrieval. The command
3365 history is automatically saved when <application>psql</application>
3366 exits and is reloaded when
3367 <application>psql</application> starts up. Tab-completion is also
3368 supported, although the completion logic makes no claim to be an
3369 <acronym>SQL</acronym> parser. The queries generated by tab-completion
3370 can also interfere with other SQL commands, e.g. <literal>SET
3371 TRANSACTION ISOLATION LEVEL</>.
3372 If for some reason you do not like the tab completion, you
3373 can turn it off by putting this in a file named
3374 <filename>.inputrc</filename> in your home directory:
3377 set disable-completion on
3380 (This is not a <application>psql</application> but a
3381 <application>Readline</application> feature. Read its documentation
3382 for further details.)
3389 <refsect1 id="app-psql-environment">
3390 <title id="app-psql-environment-title">Environment</title>
3395 <term><envar>COLUMNS</envar></term>
3399 If <literal>\pset columns</> is zero, controls the
3400 width for the <literal>wrapped</> format and width for determining
3401 if wide output requires the pager or should be switched to the
3402 vertical format in expanded auto mode.
3408 <term><envar>PAGER</envar></term>
3412 If the query results do not fit on the screen, they are piped
3413 through this command. Typical values are
3414 <literal>more</literal> or <literal>less</literal>. The default
3415 is platform-dependent. The use of the pager can be disabled by
3416 using the <command>\pset</command> command.
3422 <term><envar>PGDATABASE</envar></term>
3423 <term><envar>PGHOST</envar></term>
3424 <term><envar>PGPORT</envar></term>
3425 <term><envar>PGUSER</envar></term>
3429 Default connection parameters (see <xref linkend="libpq-envars">).
3435 <term><envar>PSQL_EDITOR</envar></term>
3436 <term><envar>EDITOR</envar></term>
3437 <term><envar>VISUAL</envar></term>
3441 Editor used by the <command>\e</command> and
3442 <command>\ef</command> commands. The variables are examined in
3443 the order listed; the first that is set is used.
3447 The built-in default editors are <filename>vi</filename> on Unix
3448 systems and <filename>notepad.exe</filename> on Windows systems.
3454 <term><envar>PSQL_EDITOR_LINENUMBER_ARG</envar></term>
3458 When <command>\e</command> or <command>\ef</command> is used
3459 with a line number argument, this variable specifies the
3460 command-line argument used to pass the starting line number to
3461 the user's editor. For editors such as <productname>Emacs</> or
3462 <productname>vi</>, this is a plus sign. Include a trailing
3463 space in the value of the variable if there needs to be space
3464 between the option name and the line number. Examples:
3466 PSQL_EDITOR_LINENUMBER_ARG='+'
3467 PSQL_EDITOR_LINENUMBER_ARG='--line '
3472 The default is <literal>+</literal> on Unix systems
3473 (corresponding to the default editor <filename>vi</filename>,
3474 and useful for many other common editors); but there is no
3475 default on Windows systems.
3481 <term><envar>PSQL_HISTORY</envar></term>
3485 Alternative location for the command history file. Tilde (<literal>~</literal>) expansion is performed.
3491 <term><envar>PSQLRC</envar></term>
3495 Alternative location of the user's <filename>.psqlrc</filename> file. Tilde (<literal>~</literal>) expansion is performed.
3501 <term><envar>SHELL</envar></term>
3505 Command executed by the <command>\!</command> command.
3511 <term><envar>TMPDIR</envar></term>
3515 Directory for storing temporary files. The default is
3516 <filename>/tmp</filename>.
3523 This utility, like most other <productname>PostgreSQL</> utilities,
3524 also uses the environment variables supported by <application>libpq</>
3525 (see <xref linkend="libpq-envars">).
3532 <title>Files</title>
3536 <term><filename>psqlrc</filename> and <filename>~/.psqlrc</filename></term>
3539 Unless it is passed an <option>-X</option> or <option>-c</option> option,
3540 <application>psql</application> attempts to read and execute commands
3541 from the system-wide startup file (<filename>psqlrc</filename>) and then
3542 the user's personal startup file (<filename>~/.psqlrc</filename>), after
3543 connecting to the database but before accepting normal commands.
3544 These files can be used to set up the client and/or the server to taste,
3545 typically with <command>\set</command> and <command>SET</command>
3549 The system-wide startup file is named <filename>psqlrc</filename> and is
3550 sought in the installation's <quote>system configuration</> directory,
3551 which is most reliably identified by running <literal>pg_config
3552 --sysconfdir</>. By default this directory will be <filename>../etc/</>
3553 relative to the directory containing
3554 the <productname>PostgreSQL</productname> executables. The name of this
3555 directory can be set explicitly via the <envar>PGSYSCONFDIR</envar>
3556 environment variable.
3559 The user's personal startup file is named <filename>.psqlrc</filename>
3560 and is sought in the invoking user's home directory. On Windows, which
3561 lacks such a concept, the personal startup file is named
3562 <filename>%APPDATA%\postgresql\psqlrc.conf</filename>.
3563 The location of the user's startup file can be set explicitly via
3564 the <envar>PSQLRC</envar> environment variable.
3567 Both the system-wide startup file and the user's personal startup file
3568 can be made <application>psql</application>-version-specific
3569 by appending a dash and the <productname>PostgreSQL</productname>
3570 major or minor release number to the file name,
3571 for example <filename>~/.psqlrc-9.2</filename> or
3572 <filename>~/.psqlrc-9.2.5</filename>. The most specific
3573 version-matching file will be read in preference to a
3574 non-version-specific file.
3580 <term><filename>.psql_history</filename></term>
3583 The command-line history is stored in the file
3584 <filename>~/.psql_history</filename>, or
3585 <filename>%APPDATA%\postgresql\psql_history</filename> on Windows.
3588 The location of the history file can be set explicitly via
3589 the <envar>PSQL_HISTORY</envar> environment variable.
3598 <title>Notes</title>
3603 In an earlier life <application>psql</application> allowed the
3604 first argument of a single-letter backslash command to start
3605 directly after the command, without intervening whitespace.
3606 As of <productname>PostgreSQL</productname> 8.4 this is no
3612 <para><application>psql</application> works best with servers of the same
3613 or an older major version. Backslash commands are particularly likely
3614 to fail if the server is of a newer version than <application>psql</>
3615 itself. However, backslash commands of the <literal>\d</> family should
3616 work with servers of versions back to 7.4, though not necessarily with
3617 servers newer than <application>psql</> itself. The general
3618 functionality of running SQL commands and displaying query results
3619 should also work with servers of a newer major version, but this cannot
3620 be guaranteed in all cases.
3623 If you want to use <application>psql</application> to connect to several
3624 servers of different major versions, it is recommended that you use the
3625 newest version of <application>psql</application>. Alternatively, you
3626 can keep a copy of <application>psql</application> from each major
3627 version around and be sure to use the version that matches the
3628 respective server. But in practice, this additional complication should
3638 <title>Notes for Windows Users</title>
3641 <application>psql</application> is built as a <quote>console
3642 application</>. Since the Windows console windows use a different
3643 encoding than the rest of the system, you must take special care
3644 when using 8-bit characters within <application>psql</application>.
3645 If <application>psql</application> detects a problematic
3646 console code page, it will warn you at startup. To change the
3647 console code page, two things are necessary:
3652 Set the code page by entering <userinput>cmd.exe /c chcp
3653 1252</userinput>. (1252 is a code page that is appropriate for
3654 German; replace it with your value.) If you are using Cygwin,
3655 you can put this command in <filename>/etc/profile</filename>.
3661 Set the console font to <literal>Lucida Console</>, because the
3662 raster font does not work with the ANSI code page.
3665 </itemizedlist></para>
3670 <refsect1 id="APP-PSQL-examples">
3671 <title id="APP-PSQL-examples-title">Examples</title>
3674 The first example shows how to spread a command over several lines of
3675 input. Notice the changing prompt:
3677 testdb=> <userinput>CREATE TABLE my_table (</userinput>
3678 testdb(> <userinput> first integer not null default 0,</userinput>
3679 testdb(> <userinput> second text)</userinput>
3680 testdb-> <userinput>;</userinput>
3683 Now look at the table definition again:
3685 testdb=> <userinput>\d my_table</userinput>
3687 Attribute | Type | Modifier
3688 -----------+---------+--------------------
3689 first | integer | not null default 0
3693 Now we change the prompt to something more interesting:
3695 testdb=> <userinput>\set PROMPT1 '%n@%m %~%R%# '</userinput>
3696 peter@localhost testdb=>
3698 Let's assume you have filled the table with data and want to take a
3701 peter@localhost testdb=> SELECT * FROM my_table;
3711 You can display tables in different ways by using the
3712 <command>\pset</command> command:
3714 peter@localhost testdb=> <userinput>\pset border 2</userinput>
3716 peter@localhost testdb=> <userinput>SELECT * FROM my_table;</userinput>
3727 peter@localhost testdb=> <userinput>\pset border 0</userinput>
3729 peter@localhost testdb=> <userinput>SELECT * FROM my_table;</userinput>
3738 peter@localhost testdb=> <userinput>\pset border 1</userinput>
3740 peter@localhost testdb=> <userinput>\pset format unaligned</userinput>
3741 Output format is unaligned.
3742 peter@localhost testdb=> <userinput>\pset fieldsep ","</userinput>
3743 Field separator is ",".
3744 peter@localhost testdb=> <userinput>\pset tuples_only</userinput>
3745 Showing only tuples.
3746 peter@localhost testdb=> <userinput>SELECT second, first FROM my_table;</userinput>
3752 Alternatively, use the short commands:
3754 peter@localhost testdb=> <userinput>\a \t \x</userinput>
3755 Output format is aligned.
3757 Expanded display is on.
3758 peter@localhost testdb=> <userinput>SELECT * FROM my_table;</userinput>
3771 </programlisting></para>