* Sample to demonstrate C functions which return setof scalar
* and setof composite.
* Joe Conway <mail@joeconway.com>
+ * And contributors:
+ * Nabil Sayegh <postgresql@e-trolley.de>
*
* Copyright 2002 by PostgreSQL Global Development Group
*
- requires anonymous composite type syntax in the FROM clause. See
the instructions in the documentation below.
- connectby(text relname, text keyid_fld, text parent_keyid_fld,
- text start_with, int max_depth [, text branch_delim])
+ connectby(text relname, text keyid_fld, text parent_keyid_fld
+ [, text orderby_fld], text start_with, int max_depth
+ [, text branch_delim])
- returns keyid, parent_keyid, level, and an optional branch string
+ and an optional serial column for ordering siblings
- requires anonymous composite type syntax in the FROM clause. See
the instructions in the documentation below.
==================================================================
Name
-connectby(text, text, text, text, int[, text]) - returns a set
+connectby(text, text, text[, text], text, text, int[, text]) - returns a set
representing a hierarchy (tree structure)
Synopsis
-connectby(text relname, text keyid_fld, text parent_keyid_fld,
- text start_with, int max_depth [, text branch_delim])
+connectby(text relname, text keyid_fld, text parent_keyid_fld
+ [, text orderby_fld], text start_with, int max_depth
+ [, text branch_delim])
Inputs
Name of the key_parent field
+ orderby_fld
+
+ If optional ordering of siblings is desired:
+ Name of the field to order siblings
+
start_with
root value of the tree input as a text value regardless of keyid_fld type
SELECT * FROM connectby('connectby_tree', 'keyid', 'parent_keyid', 'row2', 0)
AS t(keyid text, parent_keyid text, level int);
+
+ - or -
+
+ SELECT * FROM connectby('connectby_tree', 'keyid', 'parent_keyid', 'pos', 'row2', 0, '~')
+ AS t(keyid text, parent_keyid text, level int, branch text, pos int);
+
+ - or -
+
+ SELECT * FROM connectby('connectby_tree', 'keyid', 'parent_keyid', 'pos', 'row2', 0)
+ AS t(keyid text, parent_keyid text, level int, pos int);
Notes
5. The parameters representing table and field names must include double
quotes if the names are mixed-case or contain special characters.
+ 6. If sorting of siblings is desired, the orderby_fld input parameter *and*
+ a name for the resulting serial field (type INT32) in the query column
+ definition must be given.
Example usage
-CREATE TABLE connectby_tree(keyid text, parent_keyid text);
+CREATE TABLE connectby_tree(keyid text, parent_keyid text, pos int);
-INSERT INTO connectby_tree VALUES('row1',NULL);
-INSERT INTO connectby_tree VALUES('row2','row1');
-INSERT INTO connectby_tree VALUES('row3','row1');
-INSERT INTO connectby_tree VALUES('row4','row2');
-INSERT INTO connectby_tree VALUES('row5','row2');
-INSERT INTO connectby_tree VALUES('row6','row4');
-INSERT INTO connectby_tree VALUES('row7','row3');
-INSERT INTO connectby_tree VALUES('row8','row6');
-INSERT INTO connectby_tree VALUES('row9','row5');
+INSERT INTO connectby_tree VALUES('row1',NULL, 0);
+INSERT INTO connectby_tree VALUES('row2','row1', 0);
+INSERT INTO connectby_tree VALUES('row3','row1', 0);
+INSERT INTO connectby_tree VALUES('row4','row2', 1);
+INSERT INTO connectby_tree VALUES('row5','row2', 0);
+INSERT INTO connectby_tree VALUES('row6','row4', 0);
+INSERT INTO connectby_tree VALUES('row7','row3', 0);
+INSERT INTO connectby_tree VALUES('row8','row6', 0);
+INSERT INTO connectby_tree VALUES('row9','row5', 0);
--- with branch
+-- with branch, without orderby_fld
SELECT * FROM connectby('connectby_tree', 'keyid', 'parent_keyid', 'row2', 0, '~')
AS t(keyid text, parent_keyid text, level int, branch text);
keyid | parent_keyid | level | branch
row9 | row5 | 2 | row2~row5~row9
(6 rows)
--- without branch
+-- without branch, without orderby_fld
SELECT * FROM connectby('connectby_tree', 'keyid', 'parent_keyid', 'row2', 0)
AS t(keyid text, parent_keyid text, level int);
keyid | parent_keyid | level
row9 | row5 | 2
(6 rows)
+-- with branch, with orderby_fld (notice that row5 comes before row4)
+SELECT * FROM connectby('connectby_tree', 'keyid', 'parent_keyid', 'pos', 'row2', 0, '~')
+ AS t(keyid text, parent_keyid text, level int, branch text, pos int) ORDER BY t.pos;
+ keyid | parent_keyid | level | branch | pos
+-------+--------------+-------+---------------------+-----
+ row2 | | 0 | row2 | 1
+ row5 | row2 | 1 | row2~row5 | 2
+ row9 | row5 | 2 | row2~row5~row9 | 3
+ row4 | row2 | 1 | row2~row4 | 4
+ row6 | row4 | 2 | row2~row4~row6 | 5
+ row8 | row6 | 3 | row2~row4~row6~row8 | 6
+(6 rows)
+
+-- without branch, with orderby_fld (notice that row5 comes before row4)
+SELECT * FROM connectby('connectby_tree', 'keyid', 'parent_keyid', 'pos', 'row2', 0)
+ AS t(keyid text, parent_keyid text, level int, pos int) ORDER BY t.pos;
+ keyid | parent_keyid | level | pos
+-------+--------------+-------+-----
+ row2 | | 0 | 1
+ row5 | row2 | 1 | 2
+ row9 | row5 | 2 | 3
+ row4 | row2 | 1 | 4
+ row6 | row4 | 2 | 5
+ row8 | row6 | 3 | 6
+(6 rows)
+
==================================================================
-- Joe Conway
-row1 \N
-row2 row1
-row3 row1
-row4 row2
-row5 row2
-row6 row4
-row7 row3
-row8 row6
-row9 row5
+row1 \N 0
+row2 row1 0
+row3 row1 0
+row4 row2 1
+row5 row2 0
+row6 row4 0
+row7 row3 0
+row8 row6 0
+row9 row5 0
-- connectby
--
-- test connectby with text based hierarchy
-CREATE TABLE connectby_text(keyid text, parent_keyid text);
+CREATE TABLE connectby_text(keyid text, parent_keyid text, pos int);
\copy connectby_text from 'data/connectby_text.data'
--- with branch
+-- with branch, without orderby
SELECT * FROM connectby('connectby_text', 'keyid', 'parent_keyid', 'row2', 0, '~') AS t(keyid text, parent_keyid text, level int, branch text);
keyid | parent_keyid | level | branch
-------+--------------+-------+---------------------
row9 | row5 | 2 | row2~row5~row9
(6 rows)
--- without branch
+-- without branch, without orderby
SELECT * FROM connectby('connectby_text', 'keyid', 'parent_keyid', 'row2', 0) AS t(keyid text, parent_keyid text, level int);
keyid | parent_keyid | level
-------+--------------+-------
row9 | row5 | 2
(6 rows)
+-- with branch, with orderby
+SELECT * FROM connectby('connectby_text', 'keyid', 'parent_keyid', 'pos', 'row2', 0, '~') AS t(keyid text, parent_keyid text, level int, branch text, pos int) ORDER BY t.pos;
+ keyid | parent_keyid | level | branch | pos
+-------+--------------+-------+---------------------+-----
+ row2 | | 0 | row2 | 1
+ row5 | row2 | 1 | row2~row5 | 2
+ row9 | row5 | 2 | row2~row5~row9 | 3
+ row4 | row2 | 1 | row2~row4 | 4
+ row6 | row4 | 2 | row2~row4~row6 | 5
+ row8 | row6 | 3 | row2~row4~row6~row8 | 6
+(6 rows)
+
+-- without branch, with orderby
+SELECT * FROM connectby('connectby_text', 'keyid', 'parent_keyid', 'pos', 'row2', 0) AS t(keyid text, parent_keyid text, level int, pos int) ORDER BY t.pos;
+ keyid | parent_keyid | level | pos
+-------+--------------+-------+-----
+ row2 | | 0 | 1
+ row5 | row2 | 1 | 2
+ row9 | row5 | 2 | 3
+ row4 | row2 | 1 | 4
+ row6 | row4 | 2 | 5
+ row8 | row6 | 3 | 6
+(6 rows)
+
-- test connectby with int based hierarchy
CREATE TABLE connectby_int(keyid int, parent_keyid int);
\copy connectby_int from 'data/connectby_int.data'
--
-- test connectby with text based hierarchy
-CREATE TABLE connectby_text(keyid text, parent_keyid text);
+CREATE TABLE connectby_text(keyid text, parent_keyid text, pos int);
\copy connectby_text from 'data/connectby_text.data'
--- with branch
+-- with branch, without orderby
SELECT * FROM connectby('connectby_text', 'keyid', 'parent_keyid', 'row2', 0, '~') AS t(keyid text, parent_keyid text, level int, branch text);
--- without branch
+-- without branch, without orderby
SELECT * FROM connectby('connectby_text', 'keyid', 'parent_keyid', 'row2', 0) AS t(keyid text, parent_keyid text, level int);
+-- with branch, with orderby
+SELECT * FROM connectby('connectby_text', 'keyid', 'parent_keyid', 'pos', 'row2', 0, '~') AS t(keyid text, parent_keyid text, level int, branch text, pos int) ORDER BY t.pos;
+
+-- without branch, with orderby
+SELECT * FROM connectby('connectby_text', 'keyid', 'parent_keyid', 'pos', 'row2', 0) AS t(keyid text, parent_keyid text, level int, pos int) ORDER BY t.pos;
+
-- test connectby with int based hierarchy
CREATE TABLE connectby_int(keyid int, parent_keyid int);
\copy connectby_int from 'data/connectby_int.data'
* Sample to demonstrate C functions which return setof scalar
* and setof composite.
* Joe Conway <mail@joeconway.com>
+ * And contributors:
+ * Nabil Sayegh <postgresql@e-trolley.de>
*
* Copyright 2002 by PostgreSQL Global Development Group
*
int num_categories,
TupleDesc tupdesc,
MemoryContext per_query_ctx);
-static void validateConnectbyTupleDesc(TupleDesc tupdesc, bool show_branch);
+static void validateConnectbyTupleDesc(TupleDesc tupdesc, bool show_branch, bool show_serial);
static bool compatCrosstabTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2);
static bool compatConnectbyTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2);
static void get_normal_pair(float8 *x1, float8 *x2);
static Tuplestorestate *connectby(char *relname,
char *key_fld,
char *parent_key_fld,
+ char *orderby_fld,
char *branch_delim,
char *start_with,
int max_depth,
bool show_branch,
+ bool show_serial,
MemoryContext per_query_ctx,
AttInMetadata *attinmeta);
static Tuplestorestate *build_tuplestore_recursively(char *key_fld,
char *parent_key_fld,
char *relname,
+ char *orderby_fld,
char *branch_delim,
char *start_with,
char *branch,
int level,
+ int *serial,
int max_depth,
bool show_branch,
+ bool show_serial,
MemoryContext per_query_ctx,
AttInMetadata *attinmeta,
Tuplestorestate *tupstore);
*
* e.g. given table foo:
*
- * keyid parent_keyid
- * ------+--------------
- * row1 NULL
- * row2 row1
- * row3 row1
- * row4 row2
- * row5 row2
- * row6 row4
- * row7 row3
- * row8 row6
- * row9 row5
+ * keyid parent_keyid pos
+ * ------+------------+--
+ * row1 NULL 0
+ * row2 row1 0
+ * row3 row1 0
+ * row4 row2 1
+ * row5 row2 0
+ * row6 row4 0
+ * row7 row3 0
+ * row8 row6 0
+ * row9 row5 0
*
*
- * connectby(text relname, text keyid_fld, text parent_keyid_fld,
- * text start_with, int max_depth [, text branch_delim])
- * connectby('foo', 'keyid', 'parent_keyid', 'row2', 0, '~') returns:
+ * connectby(text relname, text keyid_fld, text parent_keyid_fld
+ * [, text orderby_fld], text start_with, int max_depth
+ * [, text branch_delim])
+ * connectby('foo', 'keyid', 'parent_keyid', 'pos', 'row2', 0, '~') returns:
*
- * keyid parent_id level branch
+ * keyid parent_id level branch serial
* ------+-----------+--------+-----------------------
- * row2 NULL 0 row2
- * row4 row2 1 row2~row4
- * row6 row4 2 row2~row4~row6
- * row8 row6 3 row2~row4~row6~row8
- * row5 row2 1 row2~row5
- * row9 row5 2 row2~row5~row9
+ * row2 NULL 0 row2 1
+ * row5 row2 1 row2~row5 2
+ * row9 row5 2 row2~row5~row9 3
+ * row4 row2 1 row2~row4 4
+ * row6 row4 2 row2~row4~row6 5
+ * row8 row6 3 row2~row4~row6~row8 6
*
*/
PG_FUNCTION_INFO_V1(connectby_text);
int max_depth = PG_GETARG_INT32(4);
char *branch_delim = NULL;
bool show_branch = false;
+ bool show_serial = false;
ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
TupleDesc tupdesc;
AttInMetadata *attinmeta;
tupdesc = CreateTupleDescCopy(rsinfo->expectedDesc);
/* does it meet our needs */
- validateConnectbyTupleDesc(tupdesc, show_branch);
+ validateConnectbyTupleDesc(tupdesc, show_branch, show_serial);
/* OK, use it then */
attinmeta = TupleDescGetAttInMetadata(tupdesc);
rsinfo->setResult = connectby(relname,
key_fld,
parent_key_fld,
+ NULL,
branch_delim,
start_with,
max_depth,
show_branch,
+ show_serial,
per_query_ctx,
attinmeta);
rsinfo->setDesc = tupdesc;
return (Datum) 0;
}
+PG_FUNCTION_INFO_V1(connectby_text_serial);
+Datum
+connectby_text_serial(PG_FUNCTION_ARGS)
+{
+ char *relname = GET_STR(PG_GETARG_TEXT_P(0));
+ char *key_fld = GET_STR(PG_GETARG_TEXT_P(1));
+ char *parent_key_fld = GET_STR(PG_GETARG_TEXT_P(2));
+ char *orderby_fld = GET_STR(PG_GETARG_TEXT_P(3));
+ char *start_with = GET_STR(PG_GETARG_TEXT_P(4));
+ int max_depth = PG_GETARG_INT32(5);
+ char *branch_delim = NULL;
+ bool show_branch = false;
+ bool show_serial = true;
+
+ ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
+ TupleDesc tupdesc;
+ AttInMetadata *attinmeta;
+ MemoryContext per_query_ctx;
+ MemoryContext oldcontext;
+
+ /* check to see if caller supports us returning a tuplestore */
+ if (!rsinfo || !(rsinfo->allowedModes & SFRM_Materialize))
+ elog(ERROR, "connectby: materialize mode required, but it is not "
+ "allowed in this context");
+
+ if (fcinfo->nargs == 7)
+ {
+ branch_delim = GET_STR(PG_GETARG_TEXT_P(6));
+ show_branch = true;
+ }
+ else
+ /* default is no show, tilde for the delimiter */
+ branch_delim = pstrdup("~");
+
+ per_query_ctx = rsinfo->econtext->ecxt_per_query_memory;
+ oldcontext = MemoryContextSwitchTo(per_query_ctx);
+
+ /* get the requested return tuple description */
+ tupdesc = CreateTupleDescCopy(rsinfo->expectedDesc);
+
+ /* does it meet our needs */
+ validateConnectbyTupleDesc(tupdesc, show_branch, show_serial);
+
+ /* OK, use it then */
+ attinmeta = TupleDescGetAttInMetadata(tupdesc);
+
+ /* check to see if caller supports us returning a tuplestore */
+ if (!rsinfo->allowedModes & SFRM_Materialize)
+ elog(ERROR, "connectby requires Materialize mode, but it is not "
+ "allowed in this context");
+
+ /* OK, go to work */
+ rsinfo->returnMode = SFRM_Materialize;
+ rsinfo->setResult = connectby(relname,
+ key_fld,
+ parent_key_fld,
+ orderby_fld,
+ branch_delim,
+ start_with,
+ max_depth,
+ show_branch,
+ show_serial,
+ per_query_ctx,
+ attinmeta);
+ rsinfo->setDesc = tupdesc;
+
+ MemoryContextSwitchTo(oldcontext);
+
+ /*
+ * SFRM_Materialize mode expects us to return a NULL Datum. The actual
+ * tuples are in our tuplestore and passed back through
+ * rsinfo->setResult. rsinfo->setDesc is set to the tuple description
+ * that we actually used to build our tuples with, so the caller can
+ * verify we did what it was expecting.
+ */
+ return (Datum) 0;
+}
+
+
/*
* connectby - does the real work for connectby_text()
*/
connectby(char *relname,
char *key_fld,
char *parent_key_fld,
+ char *orderby_fld,
char *branch_delim,
char *start_with,
int max_depth,
bool show_branch,
+ bool show_serial,
MemoryContext per_query_ctx,
AttInMetadata *attinmeta)
{
int ret;
MemoryContext oldcontext;
+ int serial = 1;
+
/* Connect to SPI manager */
if ((ret = SPI_connect()) < 0)
/* internal error */
tupstore = build_tuplestore_recursively(key_fld,
parent_key_fld,
relname,
+ orderby_fld,
branch_delim,
start_with,
start_with, /* current_branch */
0, /* initial level is 0 */
+ &serial, /* initial serial is 1 */
max_depth,
show_branch,
+ show_serial,
per_query_ctx,
attinmeta,
tupstore);
build_tuplestore_recursively(char *key_fld,
char *parent_key_fld,
char *relname,
+ char *orderby_fld,
char *branch_delim,
char *start_with,
char *branch,
int level,
+ int *serial,
int max_depth,
bool show_branch,
+ bool show_serial,
MemoryContext per_query_ctx,
AttInMetadata *attinmeta,
Tuplestorestate *tupstore)
StringInfo sql = makeStringInfo();
int ret;
int proc;
+ int serial_column;
if (max_depth > 0 && level > max_depth)
return tupstore;
/* Build initial sql statement */
- appendStringInfo(sql, "SELECT %s, %s FROM %s WHERE %s = '%s' AND %s IS NOT NULL",
+ if (!show_serial)
+ {
+ appendStringInfo(sql, "SELECT %s, %s FROM %s WHERE %s = '%s' AND %s IS NOT NULL",
key_fld,
parent_key_fld,
relname,
parent_key_fld,
start_with,
key_fld);
+ serial_column=0;
+ }
+ else
+ {
+ appendStringInfo(sql, "SELECT %s, %s FROM %s WHERE %s = '%s' AND %s IS NOT NULL ORDER BY %s",
+ key_fld,
+ parent_key_fld,
+ relname,
+ parent_key_fld,
+ start_with,
+ key_fld,
+ orderby_fld);
+ serial_column=1;
+ }
/* Retrieve the desired rows */
ret = SPI_exec(sql->data, 0);
char *current_key;
char *current_key_parent;
char current_level[INT32_STRLEN];
+ char serial_str[INT32_STRLEN];
char *current_branch;
char **values;
StringInfo branchstr = NULL;
chk_current_key = makeStringInfo();
if (show_branch)
- values = (char **) palloc(CONNECTBY_NCOLS * sizeof(char *));
+ values = (char **) palloc((CONNECTBY_NCOLS + serial_column) * sizeof(char *));
else
- values = (char **) palloc(CONNECTBY_NCOLS_NOBRANCH * sizeof(char *));
+ values = (char **) palloc((CONNECTBY_NCOLS_NOBRANCH + serial_column) * sizeof(char *));
/* First time through, do a little setup */
if (level == 0)
if (show_branch)
values[3] = start_with;
+ /* root starts the serial with 1 */
+ if (show_serial)
+ {
+ sprintf(serial_str, "%d", (*serial)++);
+ if (show_branch)
+ values[4] = serial_str;
+ else
+ values[3] = serial_str;
+ }
+
/* construct the tuple */
tuple = BuildTupleFromCStrings(attinmeta, values);
values[2] = current_level;
if (show_branch)
values[3] = current_branch;
+ if (show_serial)
+ {
+ sprintf(serial_str, "%d", (*serial)++);
+ if (show_branch)
+ values[4] = serial_str;
+ else
+ values[3] = serial_str;
+ }
tuple = BuildTupleFromCStrings(attinmeta, values);
tupstore = build_tuplestore_recursively(key_fld,
parent_key_fld,
relname,
+ orderby_fld,
branch_delim,
values[0],
current_branch,
level + 1,
+ serial,
max_depth,
show_branch,
+ show_serial,
per_query_ctx,
attinmeta,
tupstore);
* Check expected (query runtime) tupdesc suitable for Connectby
*/
static void
-validateConnectbyTupleDesc(TupleDesc tupdesc, bool show_branch)
+validateConnectbyTupleDesc(TupleDesc tupdesc, bool show_branch, bool show_serial)
{
+ int serial_column=0;
+
+ if (show_serial)
+ serial_column=1;
+
/* are there the correct number of columns */
if (show_branch)
{
- if (tupdesc->natts != CONNECTBY_NCOLS)
+ if (tupdesc->natts != (CONNECTBY_NCOLS + serial_column))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("invalid return type"),
}
else
{
- if (tupdesc->natts != CONNECTBY_NCOLS_NOBRANCH)
+ if (tupdesc->natts != CONNECTBY_NCOLS_NOBRANCH + serial_column)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("invalid return type"),
errdetail("Fourth column must be type %s.",
format_type_be(TEXTOID))));
+ /* check that the type of the fifth column is INT4 */
+ if (show_branch && show_serial && tupdesc->attrs[4]->atttypid != INT4OID)
+ elog(ERROR, "Query-specified return tuple not valid for Connectby: "
+ "fifth column must be type %s", format_type_be(INT4OID));
+
+ /* check that the type of the fifth column is INT4 */
+ if (!show_branch && show_serial && tupdesc->attrs[3]->atttypid != INT4OID)
+ elog(ERROR, "Query-specified return tuple not valid for Connectby: "
+ "fourth column must be type %s", format_type_be(INT4OID));
+
/* OK, the tupdesc is valid for our purposes */
}
* Sample to demonstrate C functions which return setof scalar
* and setof composite.
* Joe Conway <mail@joeconway.com>
+ * And contributors:
+ * Nabil Sayegh <postgresql@e-trolley.de>
*
* Copyright 2002 by PostgreSQL Global Development Group
*
extern Datum crosstab(PG_FUNCTION_ARGS);
extern Datum crosstab_hash(PG_FUNCTION_ARGS);
extern Datum connectby_text(PG_FUNCTION_ARGS);
+extern Datum connectby_text_serial(PG_FUNCTION_ARGS);
#endif /* TABLEFUNC_H */
RETURNS setof record
AS 'MODULE_PATHNAME','connectby_text'
LANGUAGE 'C' STABLE STRICT;
+
+-- These 2 take the name of a field to ORDER BY as 4th arg (for sorting siblings)
+
+CREATE OR REPLACE FUNCTION connectby(text,text,text,text,text,int,text)
+RETURNS setof record
+AS 'MODULE_PATHNAME','connectby_text_serial'
+LANGUAGE 'C' STABLE STRICT;
+
+CREATE OR REPLACE FUNCTION connectby(text,text,text,text,text,int)
+RETURNS setof record
+AS 'MODULE_PATHNAME','connectby_text_serial'
+LANGUAGE 'C' STABLE STRICT;
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