<!--
-$PostgreSQL: pgsql/doc/src/sgml/ref/psql-ref.sgml,v 1.130 2005/01/14 00:24:23 momjian Exp $
+$PostgreSQL: pgsql/doc/src/sgml/ref/psql-ref.sgml,v 1.131 2005/01/22 22:31:52 momjian Exp $
PostgreSQL documentation
-->
\g or terminate with semicolon to execute query
\q to quit
-testdb=>
+testdb=>
</programlisting>
</para>
types, relations (tables, views, indexes, sequences, large
objects), rules, and triggers.) For example:
<programlisting>
-=> <userinput>\dd version</userinput>
+=> <userinput>\dd version</userinput>
Object descriptions
Schema | Name | Object | Description
------------+---------+----------+---------------------------
space and followed by a newline. This can be useful to
intersperse information in the output of scripts. For example:
<programlisting>
-=> <userinput>\echo `date`</userinput>
+=> <userinput>\echo `date`</userinput>
Tue Oct 26 21:40:57 CEST 1999
</programlisting>
If the first argument is an unquoted <literal>-n</literal> the trailing
large object. Optionally, it associates the given
comment with the object. Example:
<programlisting>
-foo=> <userinput>\lo_import '/home/peter/pictures/photo.xcf' 'a picture of me'</userinput>
+foo=> <userinput>\lo_import '/home/peter/pictures/photo.xcf' 'a picture of me'</userinput>
lo_import 152801
</programlisting>
The response indicates that the large object received object ID
<application>psql</application> meta-command
<command>\set</command>:
<programlisting>
-testdb=> <userinput>\set foo bar</userinput>
+testdb=> <userinput>\set foo bar</userinput>
</programlisting>
sets the variable <literal>foo</literal> to the value
<literal>bar</literal>. To retrieve the content of the variable, precede
the name with a colon and use it as the argument of any slash
command:
<programlisting>
-testdb=> <userinput>\echo :foo</userinput>
+testdb=> <userinput>\echo :foo</userinput>
bar
</programlisting>
</para>
this is again to prepend the variable name with a colon
(<literal>:</literal>).
<programlisting>
-testdb=> <userinput>\set foo 'my_table'</userinput>
-testdb=> <userinput>SELECT * FROM :foo;</userinput>
+testdb=> <userinput>\set foo 'my_table'</userinput>
+testdb=> <userinput>SELECT * FROM :foo;</userinput>
</programlisting>
would then query the table <literal>my_table</literal>. The value of
the variable is copied literally, so it can even contain unbalanced
copy the contents of a file into a table column. First load the file into a
variable and then proceed as above.
<programlisting>
-testdb=> <userinput>\set content '\'' `cat my_file.txt` '\''</userinput>
-testdb=> <userinput>INSERT INTO my_table VALUES (:content);</userinput>
+testdb=> <userinput>\set content '\'' `cat my_file.txt` '\''</userinput>
+testdb=> <userinput>INSERT INTO my_table VALUES (:content);</userinput>
</programlisting>
One possible problem with this approach is that <filename>my_file.txt</filename>
might contain single quotes. These need to be escaped so that
they don't cause a syntax error when the second line is processed. This
could be done with the program <command>sed</command>:
<programlisting>
-testdb=> <userinput>\set content '\'' `sed -e "s/'/\\\\\\'/g" < my_file.txt` '\''</userinput>
+testdb=> <userinput>\set content '\'' `sed -e "s/'/\\\\\\'/g" < my_file.txt` '\''</userinput>
</programlisting>
Observe the correct number of backslashes (6)! It works
this way: After <application>psql</application> has parsed this
<literal>%]</literal>. Multiple pairs of these may occur within
the prompt. For example,
<programlisting>
-testdb=> \set PROMPT1 '%[%033[1;33;40m%]%n@%/%R%[%033[0m%#%] '
+testdb=> \set PROMPT1 '%[%033[1;33;40m%]%n@%/%R%[%033[0m%#%] '
</programlisting>
results in a boldfaced (<literal>1;</literal>) yellow-on-black
(<literal>33;40</literal>) prompt on VT100-compatible, color-capable
discouraged. If you get strange messages, keep this in mind.
For example
<programlisting>
-testdb=> <userinput>\foo</userinput>
+testdb=> <userinput>\foo</userinput>
Field separator is "oo".
</programlisting>
which is perhaps not what one would expect.
The first example shows how to spread a command over several lines of
input. Notice the changing prompt:
<programlisting>
-testdb=> <userinput>CREATE TABLE my_table (</userinput>
+testdb=> <userinput>CREATE TABLE my_table (</userinput>
testdb(> <userinput> first integer not null default 0,</userinput>
testdb(> <userinput> second text)</userinput>
-testdb-> <userinput>;</userinput>
+testdb-> <userinput>;</userinput>
CREATE TABLE
</programlisting>
Now look at the table definition again:
<programlisting>
-testdb=> <userinput>\d my_table</userinput>
+testdb=> <userinput>\d my_table</userinput>
Table "my_table"
Attribute | Type | Modifier
-----------+---------+--------------------
</programlisting>
Now we change the prompt to something more interesting:
<programlisting>
-testdb=> <userinput>\set PROMPT1 '%n@%m %~%R%# '</userinput>
-peter@localhost testdb=>
+testdb=> <userinput>\set PROMPT1 '%n@%m %~%R%# '</userinput>
+peter@localhost testdb=>
</programlisting>
Let's assume you have filled the table with data and want to take a
look at it:
<programlisting>
-peter@localhost testdb=> SELECT * FROM my_table;
+peter@localhost testdb=> SELECT * FROM my_table;
first | second
-------+--------
1 | one
You can display tables in different ways by using the
<command>\pset</command> command:
<programlisting>
-peter@localhost testdb=> <userinput>\pset border 2</userinput>
+peter@localhost testdb=> <userinput>\pset border 2</userinput>
Border style is 2.
-peter@localhost testdb=> <userinput>SELECT * FROM my_table;</userinput>
+peter@localhost testdb=> <userinput>SELECT * FROM my_table;</userinput>
+-------+--------+
| first | second |
+-------+--------+
+-------+--------+
(4 rows)
-peter@localhost testdb=> <userinput>\pset border 0</userinput>
+peter@localhost testdb=> <userinput>\pset border 0</userinput>
Border style is 0.
-peter@localhost testdb=> <userinput>SELECT * FROM my_table;</userinput>
+peter@localhost testdb=> <userinput>SELECT * FROM my_table;</userinput>
first second
----- ------
1 one
4 four
(4 rows)
-peter@localhost testdb=> <userinput>\pset border 1</userinput>
+peter@localhost testdb=> <userinput>\pset border 1</userinput>
Border style is 1.
-peter@localhost testdb=> <userinput>\pset format unaligned</userinput>
+peter@localhost testdb=> <userinput>\pset format unaligned</userinput>
Output format is unaligned.
-peter@localhost testdb=> <userinput>\pset fieldsep ","</userinput>
+peter@localhost testdb=> <userinput>\pset fieldsep ","</userinput>
Field separator is ",".
-peter@localhost testdb=> <userinput>\pset tuples_only</userinput>
+peter@localhost testdb=> <userinput>\pset tuples_only</userinput>
Showing only tuples.
-peter@localhost testdb=> <userinput>SELECT second, first FROM my_table;</userinput>
+peter@localhost testdb=> <userinput>SELECT second, first FROM my_table;</userinput>
one,1
two,2
three,3
</programlisting>
Alternatively, use the short commands:
<programlisting>
-peter@localhost testdb=> <userinput>\a \t \x</userinput>
+peter@localhost testdb=> <userinput>\a \t \x</userinput>
Output format is aligned.
Tuples only is off.
Expanded display is on.
-peter@localhost testdb=> <userinput>SELECT * FROM my_table;</userinput>
+peter@localhost testdb=> <userinput>SELECT * FROM my_table;</userinput>
-[ RECORD 1 ]-
first | 1
second | one
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