- 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])
+ - returns keyid, parent_keyid, level, and an optional branch string
+ - requires anonymous composite type syntax in the FROM clause. See
+ the instructions in the documentation below.
+
Documentation
==================================================================
Name
test2 | val6 | val7 |
(2 rows)
+==================================================================
+Name
+
+connectby(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])
+
+Inputs
+
+ relname
+
+ Name of the source relation
+
+ keyid_fld
+
+ Name of the key field
+
+ parent_keyid_fld
+
+ Name of the key_parent field
+
+ start_with
+
+ root value of the tree input as a text value regardless of keyid_fld type
+
+ max_depth
+
+ zero (0) for unlimited depth, otherwise restrict level to this depth
+
+ branch_delim
+
+ if optional branch value is desired, this string is used as the delimiter
+
+Outputs
+
+ Returns setof record, which must defined with a column definition
+ in the FROM clause of the SELECT statement, e.g.:
+
+ SELECT * FROM connectby('connectby_tree', 'keyid', 'parent_keyid', 'row2', 0, '~')
+ AS t(keyid text, parent_keyid text, level int, branch text);
+
+ - or -
+
+ SELECT * FROM connectby('connectby_tree', 'keyid', 'parent_keyid', 'row2', 0)
+ AS t(keyid text, parent_keyid text, level int);
+
+Notes
+
+ 1. keyid and parent_keyid must be the same data type
+
+ 2. The column definition *must* include a third column of type INT4 for
+ the level value output
+
+ 3. If the branch field is not desired, omit both the branch_delim input
+ parameter *and* the branch field in the query column definition
+
+ 4. If the branch field is desired, it must be the forth column in the query
+ column definition, and it must be type TEXT
+
+Example usage
+
+CREATE TABLE connectby_tree(keyid text, parent_keyid text);
+
+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');
+
+-- with branch
+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
+-------+--------------+-------+---------------------
+ row2 | | 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
+(6 rows)
+
+-- without branch
+SELECT * FROM connectby('connectby_tree', 'keyid', 'parent_keyid', 'row2', 0)
+ AS t(keyid text, parent_keyid text, level int);
+ keyid | parent_keyid | level
+-------+--------------+-------
+ row2 | | 0
+ row4 | row2 | 1
+ row6 | row4 | 2
+ row8 | row6 | 3
+ row5 | row2 | 1
+ row9 | row5 | 2
+(6 rows)
+
==================================================================
-- Joe Conway
---
--- show_all_settings()
---
-SELECT * FROM show_all_settings();
-
--
-- normal_rand()
--
select * from crosstab('select rowid, attribute, value from ct where rowclass = ''group1'' order by 1,2;', 2) as c(rowid text, att1 text, att2 text);
select * from crosstab('select rowid, attribute, value from ct where rowclass = ''group1'' order by 1,2;', 3) as c(rowid text, att1 text, att2 text, att3 text);
select * from crosstab('select rowid, attribute, value from ct where rowclass = ''group1'' order by 1,2;', 4) as c(rowid text, att1 text, att2 text, att3 text, att4 text);
+
+-- test connectby with text based hierarchy
+DROP TABLE connectby_tree;
+CREATE TABLE connectby_tree(keyid text, parent_keyid text);
+
+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');
+
+-- with branch
+SELECT * FROM connectby('connectby_tree', 'keyid', 'parent_keyid', 'row2', 0, '~') AS t(keyid text, parent_keyid text, level int, branch text);
+
+-- without branch
+SELECT * FROM connectby('connectby_tree', 'keyid', 'parent_keyid', 'row2', 0) AS t(keyid text, parent_keyid text, level int);
+
+-- test connectby with int based hierarchy
+DROP TABLE connectby_tree;
+CREATE TABLE connectby_tree(keyid int, parent_keyid int);
+
+INSERT INTO connectby_tree VALUES(1,NULL);
+INSERT INTO connectby_tree VALUES(2,1);
+INSERT INTO connectby_tree VALUES(3,1);
+INSERT INTO connectby_tree VALUES(4,2);
+INSERT INTO connectby_tree VALUES(5,2);
+INSERT INTO connectby_tree VALUES(6,4);
+INSERT INTO connectby_tree VALUES(7,3);
+INSERT INTO connectby_tree VALUES(8,6);
+INSERT INTO connectby_tree VALUES(9,5);
+
+-- with branch
+SELECT * FROM connectby('connectby_tree', 'keyid', 'parent_keyid', '2', 0, '~') AS t(keyid int, parent_keyid int, level int, branch text);
+
+-- without branch
+SELECT * FROM connectby('connectby_tree', 'keyid', 'parent_keyid', '2', 0) AS t(keyid int, parent_keyid int, level int);
+
#include "fmgr.h"
#include "funcapi.h"
-#include "executor/spi.h"
+#include "executor/spi.h"
+#include "miscadmin.h"
#include "utils/builtins.h"
#include "utils/guc.h"
#include "utils/lsyscache.h"
#include "tablefunc.h"
-static bool compatTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2);
+static void validateConnectbyTupleDesc(TupleDesc tupdesc, bool show_branch);
+static bool compatCrosstabTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2);
+static bool compatConnectbyTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2);
static void get_normal_pair(float8 *x1, float8 *x2);
-static TupleDesc make_crosstab_tupledesc(TupleDesc spi_tupdesc, int num_catagories);
+static TupleDesc make_crosstab_tupledesc(TupleDesc spi_tupdesc,
+ int num_catagories);
+static Tuplestorestate *connectby(char *relname,
+ char *key_fld,
+ char *parent_key_fld,
+ char *branch_delim,
+ char *start_with,
+ int max_depth,
+ bool show_branch,
+ MemoryContext per_query_ctx,
+ AttInMetadata *attinmeta);
+static Tuplestorestate *build_tuplestore_recursively(char *key_fld,
+ char *parent_key_fld,
+ char *relname,
+ char *branch_delim,
+ char *start_with,
+ char *branch,
+ int level,
+ int max_depth,
+ bool show_branch,
+ MemoryContext per_query_ctx,
+ AttInMetadata *attinmeta,
+ Tuplestorestate *tupstore);
+static char *quote_ident_cstr(char *rawstr);
typedef struct
{
} \
} while (0)
+/* sign, 10 digits, '\0' */
+#define INT32_STRLEN 12
+
/*
* normal_rand - return requested number of random values
* with a Gaussian (Normal) distribution.
* from ret_relname, at least based on number and type of
* attributes
*/
- if (!compatTupleDescs(tupdesc, spi_tupdesc))
+ if (!compatCrosstabTupleDescs(tupdesc, spi_tupdesc))
elog(ERROR, "crosstab: return and sql tuple descriptions are"
" incompatible");
}
}
+/*
+ * connectby_text - produce a result set from a hierarchical (parent/child)
+ * table.
+ *
+ * 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
+ *
+ *
+ * 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:
+ *
+ * keyid parent_id level branch
+ * ------+-----------+--------+-----------------------
+ * 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
+ *
+ */
+PG_FUNCTION_INFO_V1(connectby_text);
+
+#define CONNECTBY_NCOLS 4
+#define CONNECTBY_NCOLS_NOBRANCH 3
+
+Datum
+connectby_text(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 *start_with = GET_STR(PG_GETARG_TEXT_P(3));
+ int max_depth = PG_GETARG_INT32(4);
+ char *branch_delim = NULL;
+ bool show_branch = false;
+ ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
+ TupleDesc tupdesc;
+ AttInMetadata *attinmeta;
+ MemoryContext per_query_ctx;
+ MemoryContext oldcontext;
+
+ if (fcinfo->nargs == 6)
+ {
+ branch_delim = GET_STR(PG_GETARG_TEXT_P(5));
+ show_branch = true;
+ }
+
+ 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);
+
+ /* 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,
+ branch_delim,
+ start_with,
+ max_depth,
+ show_branch,
+ 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()
+ */
+static Tuplestorestate *
+connectby(char *relname,
+ char *key_fld,
+ char *parent_key_fld,
+ char *branch_delim,
+ char *start_with,
+ int max_depth,
+ bool show_branch,
+ MemoryContext per_query_ctx,
+ AttInMetadata *attinmeta)
+{
+ Tuplestorestate *tupstore = NULL;
+ int ret;
+ MemoryContext oldcontext;
+
+ /* Connect to SPI manager */
+ if ((ret = SPI_connect()) < 0)
+ elog(ERROR, "connectby: SPI_connect returned %d", ret);
+
+ /* switch to longer term context to create the tuple store */
+ oldcontext = MemoryContextSwitchTo(per_query_ctx);
+
+ /* initialize our tuplestore */
+ tupstore = tuplestore_begin_heap(true, SortMem);
+
+ MemoryContextSwitchTo(oldcontext);
+
+ /* now go get the whole tree */
+ tupstore = build_tuplestore_recursively(key_fld,
+ parent_key_fld,
+ relname,
+ branch_delim,
+ start_with,
+ start_with, /* current_branch */
+ 0, /* initial level is 0 */
+ max_depth,
+ show_branch,
+ per_query_ctx,
+ attinmeta,
+ tupstore);
+
+ SPI_finish();
+
+ oldcontext = MemoryContextSwitchTo(per_query_ctx);
+ tuplestore_donestoring(tupstore);
+ MemoryContextSwitchTo(oldcontext);
+
+ return tupstore;
+}
+
+static Tuplestorestate *
+build_tuplestore_recursively(char *key_fld,
+ char *parent_key_fld,
+ char *relname,
+ char *branch_delim,
+ char *start_with,
+ char *branch,
+ int level,
+ int max_depth,
+ bool show_branch,
+ MemoryContext per_query_ctx,
+ AttInMetadata *attinmeta,
+ Tuplestorestate *tupstore)
+{
+ TupleDesc tupdesc = attinmeta->tupdesc;
+ MemoryContext oldcontext;
+ StringInfo sql = makeStringInfo();
+ int ret;
+ int proc;
+
+ 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",
+ quote_ident_cstr(key_fld),
+ quote_ident_cstr(parent_key_fld),
+ quote_ident_cstr(relname),
+ quote_ident_cstr(parent_key_fld),
+ start_with,
+ quote_ident_cstr(key_fld));
+
+ /* Retrieve the desired rows */
+ ret = SPI_exec(sql->data, 0);
+ proc = SPI_processed;
+
+ /* Check for qualifying tuples */
+ if ((ret == SPI_OK_SELECT) && (proc > 0))
+ {
+ HeapTuple tuple;
+ HeapTuple spi_tuple;
+ SPITupleTable *tuptable = SPI_tuptable;
+ TupleDesc spi_tupdesc = tuptable->tupdesc;
+ int i;
+ char *current_key;
+ char *current_key_parent;
+ char current_level[INT32_STRLEN];
+ char *current_branch;
+ char **values;
+
+ if (show_branch)
+ values = (char **) palloc(CONNECTBY_NCOLS * sizeof(char *));
+ else
+ values = (char **) palloc(CONNECTBY_NCOLS_NOBRANCH * sizeof(char *));
+
+ /* First time through, do a little setup */
+ if (level == 0)
+ {
+ /*
+ * Check that return tupdesc is compatible with the one we got
+ * from the query, but only at level 0 -- no need to check more
+ * than once
+ */
+
+ if (!compatConnectbyTupleDescs(tupdesc, spi_tupdesc))
+ elog(ERROR, "connectby: return and sql tuple descriptions are "
+ "incompatible");
+
+ /* root value is the one we initially start with */
+ values[0] = start_with;
+
+ /* root value has no parent */
+ values[1] = NULL;
+
+ /* root level is 0 */
+ sprintf(current_level, "%d", level);
+ values[2] = current_level;
+
+ /* root branch is just starting root value */
+ if (show_branch)
+ values[3] = start_with;
+
+ /* construct the tuple */
+ tuple = BuildTupleFromCStrings(attinmeta, values);
+
+ /* switch to long lived context while storing the tuple */
+ oldcontext = MemoryContextSwitchTo(per_query_ctx);
+
+ /* now store it */
+ tuplestore_puttuple(tupstore, tuple);
+
+ /* now reset the context */
+ MemoryContextSwitchTo(oldcontext);
+
+ /* increment level */
+ level++;
+ }
+
+ for (i = 0; i < proc; i++)
+ {
+ StringInfo branchstr = NULL;
+
+ /* start a new branch */
+ if (show_branch)
+ {
+ branchstr = makeStringInfo();
+ appendStringInfo(branchstr, "%s", branch);
+ }
+
+ /* get the next sql result tuple */
+ spi_tuple = tuptable->vals[i];
+
+ /* get the current key and parent */
+ current_key = SPI_getvalue(spi_tuple, spi_tupdesc, 1);
+ current_key_parent = pstrdup(SPI_getvalue(spi_tuple, spi_tupdesc, 2));
+
+ /* get the current level */
+ sprintf(current_level, "%d", level);
+
+ /* extend the branch */
+ if (show_branch)
+ {
+ appendStringInfo(branchstr, "%s%s", branch_delim, current_key);
+ current_branch = branchstr->data;
+ }
+ else
+ current_branch = NULL;
+
+ /* build a tuple */
+ values[0] = pstrdup(current_key);
+ values[1] = current_key_parent;
+ values[2] = current_level;
+ if (show_branch)
+ values[3] = current_branch;
+
+ tuple = BuildTupleFromCStrings(attinmeta, values);
+
+ xpfree(current_key);
+ xpfree(current_key_parent);
+
+ /* switch to long lived context while storing the tuple */
+ oldcontext = MemoryContextSwitchTo(per_query_ctx);
+
+ /* store the tuple for later use */
+ tuplestore_puttuple(tupstore, tuple);
+
+ /* now reset the context */
+ MemoryContextSwitchTo(oldcontext);
+
+ heap_freetuple(tuple);
+
+ /* recurse using current_key_parent as the new start_with */
+ tupstore = build_tuplestore_recursively(key_fld,
+ parent_key_fld,
+ relname,
+ branch_delim,
+ values[0],
+ current_branch,
+ level + 1,
+ max_depth,
+ show_branch,
+ per_query_ctx,
+ attinmeta,
+ tupstore);
+ }
+ }
+
+ return tupstore;
+}
+
+/*
+ * Check expected (query runtime) tupdesc suitable for Connectby
+ */
+static void
+validateConnectbyTupleDesc(TupleDesc tupdesc, bool show_branch)
+{
+ /* are there the correct number of columns */
+ if (show_branch)
+ {
+ if (tupdesc->natts != CONNECTBY_NCOLS)
+ elog(ERROR, "Query-specified return tuple not valid for Connectby: "
+ "wrong number of columns");
+ }
+ else
+ {
+ if (tupdesc->natts != CONNECTBY_NCOLS_NOBRANCH)
+ elog(ERROR, "Query-specified return tuple not valid for Connectby: "
+ "wrong number of columns");
+ }
+
+ /* check that the types of the first two columns match */
+ if (tupdesc->attrs[0]->atttypid != tupdesc->attrs[1]->atttypid)
+ elog(ERROR, "Query-specified return tuple not valid for Connectby: "
+ "first two columns must be the same type");
+
+ /* check that the type of the third column is INT4 */
+ if (tupdesc->attrs[2]->atttypid != INT4OID)
+ elog(ERROR, "Query-specified return tuple not valid for Connectby: "
+ "third column must be type %s", format_type_be(INT4OID));
+
+ /* check that the type of the forth column is TEXT if applicable */
+ if (show_branch && tupdesc->attrs[3]->atttypid != TEXTOID)
+ elog(ERROR, "Query-specified return tuple not valid for Connectby: "
+ "third column must be type %s", format_type_be(TEXTOID));
+
+ /* OK, the tupdesc is valid for our purposes */
+}
+
+/*
+ * Check if spi sql tupdesc and return tupdesc are compatible
+ */
+static bool
+compatConnectbyTupleDescs(TupleDesc ret_tupdesc, TupleDesc sql_tupdesc)
+{
+ Oid ret_atttypid;
+ Oid sql_atttypid;
+
+ /* check the key_fld types match */
+ ret_atttypid = ret_tupdesc->attrs[0]->atttypid;
+ sql_atttypid = sql_tupdesc->attrs[0]->atttypid;
+ if (ret_atttypid != sql_atttypid)
+ elog(ERROR, "compatConnectbyTupleDescs: SQL key field datatype does "
+ "not match return key field datatype");
+
+ /* check the parent_key_fld types match */
+ ret_atttypid = ret_tupdesc->attrs[1]->atttypid;
+ sql_atttypid = sql_tupdesc->attrs[1]->atttypid;
+ if (ret_atttypid != sql_atttypid)
+ elog(ERROR, "compatConnectbyTupleDescs: SQL parent key field datatype "
+ "does not match return parent key field datatype");
+
+ /* OK, the two tupdescs are compatible for our purposes */
+ return true;
+}
+
/*
* Check if two tupdescs match in type of attributes
*/
static bool
-compatTupleDescs(TupleDesc ret_tupdesc, TupleDesc sql_tupdesc)
+compatCrosstabTupleDescs(TupleDesc ret_tupdesc, TupleDesc sql_tupdesc)
{
int i;
Form_pg_attribute ret_attr;
ret_atttypid = ret_tupdesc->attrs[0]->atttypid;
sql_atttypid = sql_tupdesc->attrs[0]->atttypid;
if (ret_atttypid != sql_atttypid)
- elog(ERROR, "compatTupleDescs: SQL rowid datatype does not match"
+ elog(ERROR, "compatCrosstabTupleDescs: SQL rowid datatype does not match"
" return rowid datatype");
/*
return tupdesc;
}
+/*
+ * Return a properly quoted identifier.
+ * Uses quote_ident in quote.c
+ */
+static char *
+quote_ident_cstr(char *rawstr)
+{
+ text *rawstr_text;
+ text *result_text;
+ char *result;
+
+ rawstr_text = DatumGetTextP(DirectFunctionCall1(textin, CStringGetDatum(rawstr)));
+ result_text = DatumGetTextP(DirectFunctionCall1(quote_ident, PointerGetDatum(rawstr_text)));
+ result = DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(result_text)));
+
+ return result;
+}
projects / users / rhaas / postgres.git / commitdiff