postgresql/src/include/parser/parse_cte.h

/*-------------------------------------------------------------------------
 *
 * parse_cte.h
 *	  handle CTEs (common table expressions) in parser
 *
 *
 * Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * $PostgreSQL: pgsql/src/include/parser/parse_cte.h,v 1.4 2010/01/02 16:58:07 momjian Exp $
 *
 *-------------------------------------------------------------------------
 */
#ifndef PARSE_CTE_H
#define PARSE_CTE_H

#include "parser/parse_node.h"

extern List *transformWithClause(ParseState *pstate, WithClause *withClause);

extern void analyzeCTETargetList(ParseState *pstate, CommonTableExpr *cte,
								 List *tlist);

#endif   /* PARSE_CTE_H */
Implement SQL-standard WITH clauses, including WITH RECURSIVE. There are some unimplemented aspects: recursive queries must use UNION ALL (should allow UNION too), and we don't have SEARCH or CYCLE clauses. These might or might not get done for 8.4, but even without them it's a pretty useful feature. There are also a couple of small loose ends and definitional quibbles, which I'll send a memo about to pgsql-hackers shortly. But let's land the patch now so we can get on with other development. Yoshiyuki Asaba, with lots of help from Tatsuo Ishii and Tom Lane 2008-10-04 23:56:55 +02:00			`/*-------------------------------------------------------------------------`
			`*`
			`* parse_cte.h`
			`* handle CTEs (common table expressions) in parser`
			`*`
			`*`
Update copyright for the year 2010. 2010-01-02 17:58:17 +01:00			`* Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group`
Implement SQL-standard WITH clauses, including WITH RECURSIVE. There are some unimplemented aspects: recursive queries must use UNION ALL (should allow UNION too), and we don't have SEARCH or CYCLE clauses. These might or might not get done for 8.4, but even without them it's a pretty useful feature. There are also a couple of small loose ends and definitional quibbles, which I'll send a memo about to pgsql-hackers shortly. But let's land the patch now so we can get on with other development. Yoshiyuki Asaba, with lots of help from Tatsuo Ishii and Tom Lane 2008-10-04 23:56:55 +02:00			`* Portions Copyright (c) 1994, Regents of the University of California`
			`*`
Update copyright for the year 2010. 2010-01-02 17:58:17 +01:00			`* $PostgreSQL: pgsql/src/include/parser/parse_cte.h,v 1.4 2010/01/02 16:58:07 momjian Exp $`
Implement SQL-standard WITH clauses, including WITH RECURSIVE. There are some unimplemented aspects: recursive queries must use UNION ALL (should allow UNION too), and we don't have SEARCH or CYCLE clauses. These might or might not get done for 8.4, but even without them it's a pretty useful feature. There are also a couple of small loose ends and definitional quibbles, which I'll send a memo about to pgsql-hackers shortly. But let's land the patch now so we can get on with other development. Yoshiyuki Asaba, with lots of help from Tatsuo Ishii and Tom Lane 2008-10-04 23:56:55 +02:00			`*`
			`*-------------------------------------------------------------------------`
			`*/`
			`#ifndef PARSE_CTE_H`
			`#define PARSE_CTE_H`

			`#include "parser/parse_node.h"`

			`extern List transformWithClause(ParseState pstate, WithClause *withClause);`

Fix bug with WITH RECURSIVE immediately inside WITH RECURSIVE. 99% of the code was already okay with this, but the hack that obtained the output column types of a recursive union in advance of doing real parse analysis of the recursive union forgot to handle the case where there was an inner WITH clause available to the non-recursive term. Best fix seems to be to refactor so that we don't need the "throwaway" parse analysis step at all. Instead, teach the transformSetOperationStmt code to set up the CTE's output column information after it's processed the non-recursive term normally. Per report from David Fetter. 2009-09-09 05:32:52 +02:00			`extern void analyzeCTETargetList(ParseState pstate, CommonTableExpr cte,`
			`List *tlist);`

Implement SQL-standard WITH clauses, including WITH RECURSIVE. There are some unimplemented aspects: recursive queries must use UNION ALL (should allow UNION too), and we don't have SEARCH or CYCLE clauses. These might or might not get done for 8.4, but even without them it's a pretty useful feature. There are also a couple of small loose ends and definitional quibbles, which I'll send a memo about to pgsql-hackers shortly. But let's land the patch now so we can get on with other development. Yoshiyuki Asaba, with lots of help from Tatsuo Ishii and Tom Lane 2008-10-04 23:56:55 +02:00			`#endif /* PARSE_CTE_H */`