Extend COPY to support COPY (SELECT ...) TO ...

Bernd Helmle

src/backend/nodes/copyfuncs.c

@@ -15,7 +15,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/nodes/copyfuncs.c,v 1.349 2006/08/25 04:06:49 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/copyfuncs.c,v 1.350 2006/08/30 23:34:21 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1934,6 +1934,7 @@ _copyCopyStmt(CopyStmt *from)
 	CopyStmt   *newnode = makeNode(CopyStmt);
 
 	COPY_NODE_FIELD(relation);
+	COPY_NODE_FIELD(query);
 	COPY_NODE_FIELD(attlist);
 	COPY_SCALAR_FIELD(is_from);
 	COPY_STRING_FIELD(filename);

src/backend/nodes/equalfuncs.c

@@ -18,7 +18,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/nodes/equalfuncs.c,v 1.283 2006/08/25 04:06:49 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/equalfuncs.c,v 1.284 2006/08/30 23:34:21 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -863,6 +863,7 @@ static bool
 _equalCopyStmt(CopyStmt *a, CopyStmt *b)
 {
 	COMPARE_NODE_FIELD(relation);
+	COMPARE_NODE_FIELD(query);
 	COMPARE_NODE_FIELD(attlist);
 	COMPARE_SCALAR_FIELD(is_from);
 	COMPARE_STRING_FIELD(filename);

src/backend/parser/analyze.c

@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- *	$PostgreSQL: pgsql/src/backend/parser/analyze.c,v 1.348 2006/08/25 04:06:51 tgl Exp $
+ *	$PostgreSQL: pgsql/src/backend/parser/analyze.c,v 1.349 2006/08/30 23:34:21 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -341,6 +341,19 @@ transformStmt(ParseState *pstate, Node *parseTree,
 			}
 			break;
 
+		case T_CopyStmt:
+			{
+				CopyStmt *n = (CopyStmt *) parseTree;
+
+				result = makeNode(Query);
+				result->commandType = CMD_UTILITY;
+				if (n->query)
+					n->query = transformStmt(pstate, (Node *) n->query,
+											 extras_before, extras_after);
+				result->utilityStmt = (Node *) parseTree;
+			}
+			break;
+
 		case T_AlterTableStmt:
 			result = transformAlterTableStmt(pstate,
 											 (AlterTableStmt *) parseTree,

src/backend/parser/gram.y

@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.558 2006/08/25 04:06:51 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.559 2006/08/30 23:34:21 tgl Exp $
  *
  * HISTORY
  *	  AUTHOR			DATE			MAJOR EVENT
@@ -1614,11 +1614,15 @@ ClosePortalStmt:
 /*****************************************************************************
  *
  *		QUERY :
- *				COPY <relname> ['(' columnList ')'] FROM/TO [WITH options]
+ *				COPY relname ['(' columnList ')'] FROM/TO file [WITH options]
  *
  *				BINARY, OIDS, and DELIMITERS kept in old locations
  *				for backward compatibility.  2002-06-18
  *
+ *				COPY ( SELECT ... ) TO file [WITH options]
+ *				This form doesn't have the backwards-compatible option
+ *				syntax.
+ *
  *****************************************************************************/
 
 CopyStmt:	COPY opt_binary qualified_name opt_column_list opt_oids
@@ -1626,6 +1630,7 @@ CopyStmt:	COPY opt_binary qualified_name opt_column_list opt_oids
 				{
 					CopyStmt *n = makeNode(CopyStmt);
 					n->relation = $3;
+					n->query = NULL;
 					n->attlist = $4;
 					n->is_from = $6;
 					n->filename = $7;
@@ -1642,6 +1647,18 @@ CopyStmt:	COPY opt_binary qualified_name opt_column_list opt_oids
 						n->options = list_concat(n->options, $10);
 					$$ = (Node *)n;
 				}
+			| COPY select_with_parens TO copy_file_name opt_with
+			  copy_opt_list
+				{
+					CopyStmt *n = makeNode(CopyStmt);
+					n->relation = NULL;
+					n->query = (Query *) $2;
+					n->attlist = NIL;
+					n->is_from = false;
+					n->filename = $4;
+					n->options = $6;
+					$$ = (Node *)n;
+				}
 		;
 
 copy_from:
@@ -1652,7 +1669,7 @@ copy_from:
 /*
  * copy_file_name NULL indicates stdio is used. Whether stdin or stdout is
  * used depends on the direction. (It really doesn't make sense to copy from
- * stdout. We silently correct the "typo".		 - AY 9/94
+ * stdout. We silently correct the "typo".)		 - AY 9/94
  */
 copy_file_name:
 			Sconst									{ $$ = $1; }

src/backend/tcop/dest.c

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/tcop/dest.c,v 1.69 2006/08/12 02:52:05 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/tcop/dest.c,v 1.70 2006/08/30 23:34:21 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -30,6 +30,7 @@
 
 #include "access/printtup.h"
 #include "access/xact.h"
+#include "commands/copy.h"
 #include "executor/executor.h"
 #include "executor/tstoreReceiver.h"
 #include "libpq/libpq.h"
@@ -128,6 +129,9 @@ CreateDestReceiver(CommandDest dest, Portal portal)
 
 		case DestIntoRel:
 			return CreateIntoRelDestReceiver();
+
+		case DestCopyOut:
+			return CreateCopyDestReceiver();
 	}
 
 	/* should never get here */
@@ -153,6 +157,7 @@ EndCommand(const char *commandTag, CommandDest dest)
 		case DestSPI:
 		case DestTuplestore:
 		case DestIntoRel:
+		case DestCopyOut:
 			break;
 	}
 }
@@ -192,6 +197,7 @@ NullCommand(CommandDest dest)
 		case DestSPI:
 		case DestTuplestore:
 		case DestIntoRel:
+		case DestCopyOut:
 			break;
 	}
 }
@@ -233,6 +239,7 @@ ReadyForQuery(CommandDest dest)
 		case DestSPI:
 		case DestTuplestore:
 		case DestIntoRel:
+		case DestCopyOut:
 			break;
 	}
 }

src/bin/psql/copy.c

@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2000-2006, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/bin/psql/copy.c,v 1.67 2006/08/29 15:19:50 tgl Exp $
+ * $PostgreSQL: pgsql/src/bin/psql/copy.c,v 1.68 2006/08/30 23:34:22 tgl Exp $
  */
 #include "postgres_fe.h"
 #include "copy.h"
@@ -39,6 +39,9 @@
  *	\copy tablename [(columnlist)] from|to filename
  *	  [ with ] [ binary ] [ oids ] [ delimiter [as] char ] [ null [as] string ]
  *
+ *	\copy ( select stmt ) to filename
+ *	  [ with ] [ binary ] [ delimiter [as] char ] [ null [as] string ]
+ *
  * The pre-7.3 syntax was:
  *	\copy [ binary ] tablename [(columnlist)] [with oids] from|to filename
  *		[ [using] delimiters char ] [ with null as string ]
@@ -142,6 +145,26 @@ parse_slash_copy(const char *args)
 
 	result->table = pg_strdup(token);
 
+	/* Handle COPY (SELECT) case */
+	if (token[0] == '(')
+	{
+		int	parens = 1;
+
+		while (parens > 0)
+		{
+			token = strtokx(NULL, whitespace, ".,()", "\"'",
+							nonstd_backslash, true, false, pset.encoding);
+			if (!token)
+				goto error;
+			if (token[0] == '(')
+				parens++;
+			else if (token[0] == ')')
+				parens--;
+			xstrcat(&result->table, " ");
+			xstrcat(&result->table, token);
+		}
+	}
+
 	token = strtokx(NULL, whitespace, ".,()", "\"",
 					0, false, false, pset.encoding);
 	if (!token)

src/include/commands/copy.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/commands/copy.h,v 1.27 2006/03/05 15:58:55 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/commands/copy.h,v 1.28 2006/08/30 23:34:22 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -15,8 +15,11 @@
 #define COPY_H
 
 #include "nodes/parsenodes.h"
+#include "tcop/dest.h"
 
 
 extern uint64 DoCopy(const CopyStmt *stmt);
 
+extern DestReceiver *CreateCopyDestReceiver(void);
+
 #endif   /* COPY_H */

src/include/nodes/parsenodes.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/nodes/parsenodes.h,v 1.325 2006/08/25 04:06:56 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/parsenodes.h,v 1.326 2006/08/30 23:34:22 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1012,16 +1012,22 @@ typedef struct GrantRoleStmt
 
 /* ----------------------
  *		Copy Statement
+ *
+ * We support "COPY relation FROM file", "COPY relation TO file", and
+ * "COPY (query) TO file".  In any given CopyStmt, exactly one of "relation"
+ * and "query" must be non-NULL.  Note: "query" is a SelectStmt before
+ * parse analysis, and a Query afterwards.
  * ----------------------
  */
 typedef struct CopyStmt
 {
 	NodeTag		type;
 	RangeVar   *relation;		/* the relation to copy */
+	Query	   *query;			/* the query to copy */
 	List	   *attlist;		/* List of column names (as Strings), or NIL
 								 * for all columns */
 	bool		is_from;		/* TO or FROM */
-	char	   *filename;		/* if NULL, use stdin/stdout */
+	char	   *filename;		/* filename, or NULL for STDIN/STDOUT */
 	List	   *options;		/* List of DefElem nodes */
 } CopyStmt;
 

src/include/tcop/dest.h

@@ -54,7 +54,7 @@
  * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/tcop/dest.h,v 1.51 2006/08/12 02:52:06 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/tcop/dest.h,v 1.52 2006/08/30 23:34:22 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -85,7 +85,8 @@ typedef enum
 	DestRemoteExecute,			/* sent to frontend, in Execute command */
 	DestSPI,					/* results sent to SPI manager */
 	DestTuplestore,				/* results sent to Tuplestore */
-	DestIntoRel					/* results sent to relation (SELECT INTO) */
+	DestIntoRel,				/* results sent to relation (SELECT INTO) */
+	DestCopyOut					/* results sent to COPY TO code */
 } CommandDest;
 
 /* ----------------

src/test/regress/expected/copyselect.out

@@ -0,0 +1,126 @@
+--
+-- Test cases for COPY (select) TO
+--
+create table test1 (id serial, t text);
+NOTICE:  CREATE TABLE will create implicit sequence "test1_id_seq" for serial column "test1.id"
+insert into test1 (t) values ('a');
+insert into test1 (t) values ('b');
+insert into test1 (t) values ('c');
+insert into test1 (t) values ('d');
+insert into test1 (t) values ('e');
+create table test2 (id serial, t text);
+NOTICE:  CREATE TABLE will create implicit sequence "test2_id_seq" for serial column "test2.id"
+insert into test2 (t) values ('A');
+insert into test2 (t) values ('B');
+insert into test2 (t) values ('C');
+insert into test2 (t) values ('D');
+insert into test2 (t) values ('E');
+create view v_test1
+as select 'v_'||t from test1;
+--
+-- Test COPY table TO
+--
+copy test1 to stdout;
+1	a
+2	b
+3	c
+4	d
+5	e
+--
+-- This should fail
+--
+copy v_test1 to stdout;
+ERROR:  cannot copy from view "v_test1"
+HINT:  Try the COPY (SELECT ...) TO variant.
+--
+-- Test COPY (select) TO
+--
+copy (select t from test1 where id=1) to stdout;
+a
+--
+-- Test COPY (select for update) TO
+--
+copy (select t from test1 where id=3 for update) to stdout;
+c
+--
+-- This should fail
+--
+copy (select t into temp test3 from test1 where id=3) to stdout;
+ERROR:  COPY (SELECT INTO) is not supported
+--
+-- This should fail
+--
+copy (select * from test1) from stdin;
+ERROR:  syntax error at or near "from"
+LINE 1: copy (select * from test1) from stdin;
+                                   ^
+--
+-- This should fail
+--
+copy (select * from test1) (t,id) to stdout;
+ERROR:  syntax error at or near "("
+LINE 1: copy (select * from test1) (t,id) to stdout;
+                                   ^
+--
+-- Test JOIN
+--
+copy (select * from test1 join test2 using (id)) to stdout;
+1	a	A
+2	b	B
+3	c	C
+4	d	D
+5	e	E
+--
+-- Test UNION SELECT
+--
+copy (select t from test1 where id = 1 UNION select * from v_test1) to stdout;
+a
+v_a
+v_b
+v_c
+v_d
+v_e
+--
+-- Test subselect
+--
+copy (select * from (select t from test1 where id = 1 UNION select * from v_test1) t1) to stdout;
+a
+v_a
+v_b
+v_c
+v_d
+v_e
+--
+-- Test headers, CSV and quotes
+--
+copy (select t from test1 where id = 1) to stdout csv header force quote t;
+t
+"a"
+--
+-- Test psql builtins, plain table
+--
+\copy test1 to stdout
+1	a
+2	b
+3	c
+4	d
+5	e
+--
+-- This should fail
+--
+\copy v_test1 to stdout
+ERROR:  cannot copy from view "v_test1"
+HINT:  Try the COPY (SELECT ...) TO variant.
+\copy: ERROR:  cannot copy from view "v_test1"
+HINT:  Try the COPY (SELECT ...) TO variant.
+-- 
+-- Test \copy (select ...)
+--
+\copy (select "id",'id','id""'||t,(id + 1)*id,t,"test1"."t" from test1 where id=3) to stdout
+3	id	id""c	12	c	c
+--
+-- Drop everything
+--
+drop table test2;
+drop view v_test1;
+drop table test1;

src/test/regress/parallel_schedule

@@ -1,6 +1,6 @@
 # ----------
 # The first group of parallel test
-# $PostgreSQL: pgsql/src/test/regress/parallel_schedule,v 1.34 2006/08/12 02:52:06 tgl Exp $
+# $PostgreSQL: pgsql/src/test/regress/parallel_schedule,v 1.35 2006/08/30 23:34:22 tgl Exp $
 # ----------
 test: boolean char name varchar text int2 int4 int8 oid float4 float8 bit numeric
 
@@ -34,7 +34,7 @@ test: create_function_2
 # execute two copy tests parallel, to check that copy itself
 # is concurrent safe.
 # ----------
-test: copy
+test: copy copyselect
 
 # ----------
 # The third group of parallel test

src/test/regress/serial_schedule

@@ -1,4 +1,4 @@
-# $PostgreSQL: pgsql/src/test/regress/serial_schedule,v 1.32 2006/08/12 02:52:06 tgl Exp $
+# $PostgreSQL: pgsql/src/test/regress/serial_schedule,v 1.33 2006/08/30 23:34:22 tgl Exp $
 # This should probably be in an order similar to parallel_schedule.
 test: boolean
 test: char
@@ -43,6 +43,7 @@ test: create_type
 test: create_table
 test: create_function_2
 test: copy
+test: copyselect
 test: constraints
 test: triggers
 test: create_misc

src/test/regress/sql/copyselect.sql

@@ -0,0 +1,82 @@
+--
+-- Test cases for COPY (select) TO
+--
+create table test1 (id serial, t text);
+insert into test1 (t) values ('a');
+insert into test1 (t) values ('b');
+insert into test1 (t) values ('c');
+insert into test1 (t) values ('d');
+insert into test1 (t) values ('e');
+
+create table test2 (id serial, t text);
+insert into test2 (t) values ('A');
+insert into test2 (t) values ('B');
+insert into test2 (t) values ('C');
+insert into test2 (t) values ('D');
+insert into test2 (t) values ('E');
+
+create view v_test1
+as select 'v_'||t from test1;
+
+--
+-- Test COPY table TO
+--
+copy test1 to stdout;
+--
+-- This should fail
+--
+copy v_test1 to stdout;
+--
+-- Test COPY (select) TO
+--
+copy (select t from test1 where id=1) to stdout;
+--
+-- Test COPY (select for update) TO
+--
+copy (select t from test1 where id=3 for update) to stdout;
+--
+-- This should fail
+--
+copy (select t into temp test3 from test1 where id=3) to stdout;
+--
+-- This should fail
+--
+copy (select * from test1) from stdin;
+--
+-- This should fail
+--
+copy (select * from test1) (t,id) to stdout;
+--
+-- Test JOIN
+--
+copy (select * from test1 join test2 using (id)) to stdout;
+--
+-- Test UNION SELECT
+--
+copy (select t from test1 where id = 1 UNION select * from v_test1) to stdout;
+--
+-- Test subselect
+--
+copy (select * from (select t from test1 where id = 1 UNION select * from v_test1) t1) to stdout;
+--
+-- Test headers, CSV and quotes
+--
+copy (select t from test1 where id = 1) to stdout csv header force quote t;
+--
+-- Test psql builtins, plain table
+--
+\copy test1 to stdout
+--
+-- This should fail
+--
+\copy v_test1 to stdout
+-- 
+-- Test \copy (select ...)
+--
+\copy (select "id",'id','id""'||t,(id + 1)*id,t,"test1"."t" from test1 where id=3) to stdout
+--
+-- Drop everything
+--
+drop table test2;
+drop view v_test1;
+drop table test1;