mirror of
https://github.com/postgres/postgres.git
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UPDATE ... SET <col> = DEFAULT
Rod Taylor
This commit is contained in:
Bruce Momjian
@ -1,5 +1,5 @@
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<!--
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$Header: /cvsroot/pgsql/doc/src/sgml/ref/update.sgml,v 1.21 2003/04/26 23:56:51 petere Exp $
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$Header: /cvsroot/pgsql/doc/src/sgml/ref/update.sgml,v 1.22 2003/06/25 04:19:24 momjian Exp $
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PostgreSQL documentation
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-->
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@ -16,7 +16,7 @@ PostgreSQL documentation
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<refsynopsisdiv>
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<synopsis>
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UPDATE [ ONLY ] <replaceable class="PARAMETER">table</replaceable> SET <replaceable class="PARAMETER">column</replaceable> = <replaceable class="PARAMETER">expression</replaceable> [, ...]
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UPDATE [ ONLY ] <replaceable class="PARAMETER">table</replaceable> SET <replaceable class="PARAMETER">column</replaceable> = { <replaceable class="PARAMETER">expression</replaceable> | DEFAULT } [, ...]
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[ FROM <replaceable class="PARAMETER">fromlist</replaceable> ]
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[ WHERE <replaceable class="PARAMETER">condition</replaceable> ]
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</synopsis>
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@ -77,6 +77,15 @@ UPDATE [ ONLY ] <replaceable class="PARAMETER">table</replaceable> SET <replacea
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><literal>DEFAULT</literal></term>
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<listitem>
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<para>
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This column will be filled with its default value.
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><replaceable class="PARAMETER">fromlist</replaceable></term>
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<listitem>
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@ -15,7 +15,7 @@
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.254 2003/06/25 03:40:17 momjian Exp $
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* $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.255 2003/06/25 04:19:24 momjian Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -1661,10 +1661,10 @@ _copyFuncWithArgs(FuncWithArgs *from)
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return newnode;
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}
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static InsertDefault *
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_copyInsertDefault(InsertDefault *from)
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static SetToDefault *
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_copySetToDefault(SetToDefault *from)
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{
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InsertDefault *newnode = makeNode(InsertDefault);
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SetToDefault *newnode = makeNode(SetToDefault);
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return newnode;
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}
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@ -2942,8 +2942,8 @@ copyObject(void *from)
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case T_FuncWithArgs:
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retval = _copyFuncWithArgs(from);
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break;
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case T_InsertDefault:
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retval = _copyInsertDefault(from);
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case T_SetToDefault:
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retval = _copySetToDefault(from);
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break;
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default:
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@ -18,7 +18,7 @@
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/nodes/equalfuncs.c,v 1.197 2003/06/25 03:40:17 momjian Exp $
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* $Header: /cvsroot/pgsql/src/backend/nodes/equalfuncs.c,v 1.198 2003/06/25 04:19:24 momjian Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -728,7 +728,7 @@ _equalFuncWithArgs(FuncWithArgs *a, FuncWithArgs *b)
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}
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static bool
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_equalInsertDefault(InsertDefault *a, InsertDefault *b)
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_equalSetToDefault(SetToDefault *a, SetToDefault *b)
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{
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return true;
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}
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@ -2055,8 +2055,8 @@ equal(void *a, void *b)
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case T_FuncWithArgs:
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retval = _equalFuncWithArgs(a, b);
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break;
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case T_InsertDefault:
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retval = _equalInsertDefault(a, b);
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case T_SetToDefault:
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retval = _equalSetToDefault(a, b);
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break;
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default:
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@ -6,7 +6,7 @@
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* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* $Header: /cvsroot/pgsql/src/backend/parser/analyze.c,v 1.276 2003/06/25 03:40:17 momjian Exp $
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* $Header: /cvsroot/pgsql/src/backend/parser/analyze.c,v 1.277 2003/06/25 04:19:24 momjian Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -660,23 +660,9 @@ transformInsertStmt(ParseState *pstate, InsertStmt *stmt,
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col = (ResTarget *) lfirst(icolumns);
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Assert(IsA(col, ResTarget));
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/*
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* When the value is to be set to the column default we can simply
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* drop the TLE now and handle it later on using methods for missing
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* columns.
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*/
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if (IsA(tle, InsertDefault))
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{
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qry->targetList = lremove(tle, qry->targetList);
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/* Note: the stmt->cols list is not adjusted to match */
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}
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else
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{
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/* Normal case */
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Assert(!tle->resdom->resjunk);
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updateTargetListEntry(pstate, tle, col->name, lfirsti(attnos),
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col->indirection);
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}
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Assert(!tle->resdom->resjunk);
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updateTargetListEntry(pstate, tle, col->name, lfirsti(attnos),
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col->indirection);
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icolumns = lnext(icolumns);
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attnos = lnext(attnos);
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@ -2431,10 +2417,12 @@ transformUpdateStmt(ParseState *pstate, UpdateStmt *stmt)
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if (origTargetList == NIL)
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elog(ERROR, "UPDATE target count mismatch --- internal error");
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origTarget = (ResTarget *) lfirst(origTargetList);
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updateTargetListEntry(pstate, tle, origTarget->name,
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attnameAttNum(pstate->p_target_relation,
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origTarget->name, true),
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origTarget->indirection);
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origTargetList = lnext(origTargetList);
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}
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if (origTargetList != NIL)
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@ -11,7 +11,7 @@
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.419 2003/06/25 03:40:18 momjian Exp $
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* $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.420 2003/06/25 04:19:24 momjian Exp $
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*
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* HISTORY
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* AUTHOR DATE MAJOR EVENT
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@ -6945,6 +6945,15 @@ update_target_el:
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$$->indirection = $2;
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$$->val = (Node *)$4;
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}
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| ColId opt_indirection '=' DEFAULT
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{
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SetToDefault *def = makeNode(SetToDefault);
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$$ = makeNode(ResTarget);
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$$->name = $1;
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$$->indirection = NULL;
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$$->val = (Node *)def;
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}
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;
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insert_target_list:
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@ -6956,7 +6965,7 @@ insert_target_el:
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target_el { $$ = $1; }
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| DEFAULT
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{
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InsertDefault *def = makeNode(InsertDefault);
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SetToDefault *def = makeNode(SetToDefault);
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$$ = makeNode(ResTarget);
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$$->name = NULL;
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$$->indirection = NULL;
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@ -8,7 +8,7 @@
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/parser/parse_target.c,v 1.102 2003/05/31 19:03:34 tgl Exp $
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* $Header: /cvsroot/pgsql/src/backend/parser/parse_target.c,v 1.103 2003/06/25 04:19:24 momjian Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -177,19 +177,24 @@ transformTargetList(ParseState *pstate, List *targetlist)
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false));
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}
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}
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else if (IsA(res->val, InsertDefault))
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else if (IsA(res->val, SetToDefault))
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{
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InsertDefault *newnode = makeNode(InsertDefault);
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/*
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* If this is a DEFAULT element, we make a junk entry which
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* will get dropped on return to transformInsertStmt().
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* If this is a DEFAULT element, we make a standard entry using
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* the default for the target expression. rewriteTargetList will
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* substitute the columns default for this expression.
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*/
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p_target = lappend(p_target, newnode);
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p_target = lappend(p_target,
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makeTargetEntry(makeResdom((AttrNumber) pstate->p_next_resno++,
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UNKNOWNOID,
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-1,
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res->name,
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false),
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(Expr *) res->val));
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}
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else
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{
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/* Everything else but ColumnRef and InsertDefault */
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/* Everything else but ColumnRef and SetToDefault */
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p_target = lappend(p_target,
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transformTargetEntry(pstate,
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res->val,
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@ -321,9 +326,10 @@ updateTargetListEntry(ParseState *pstate,
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int attrno,
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List *indirection)
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{
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Oid type_id = exprType((Node *) tle->expr); /* type of value provided */
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Oid type_id; /* type of value provided */
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Oid attrtype; /* type of target column */
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int32 attrtypmod;
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bool isDefault = false;
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Resdom *resnode = tle->resdom;
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Relation rd = pstate->p_target_relation;
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@ -333,6 +339,17 @@ updateTargetListEntry(ParseState *pstate,
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attrtype = attnumTypeId(rd, attrno);
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attrtypmod = rd->rd_att->attrs[attrno - 1]->atttypmod;
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/* The type of the default column is equivalent to that of the column */
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if (tle->expr != NULL && IsA(tle->expr, SetToDefault))
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{
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type_id = attrtype;
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isDefault = true;
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}
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/* Otherwise the expression holds the type */
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else
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type_id = exprType((Node *) tle->expr);
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/*
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* If there are subscripts on the target column, prepare an array
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* assignment expression. This will generate an array value that the
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@ -383,7 +400,7 @@ updateTargetListEntry(ParseState *pstate,
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* coercion. But accept InvalidOid, which indicates the source is
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* a NULL constant. (XXX is that still true?)
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*/
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if (type_id != InvalidOid)
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if (!isDefault && type_id != InvalidOid)
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{
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tle->expr = (Expr *)
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coerce_to_target_type(pstate,
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@ -7,7 +7,7 @@
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteHandler.c,v 1.120 2003/05/02 20:54:35 tgl Exp $
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* $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteHandler.c,v 1.121 2003/06/25 04:19:24 momjian Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -307,7 +307,25 @@ rewriteTargetList(Query *parsetree, Relation target_relation)
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{
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Assert(strcmp(resdom->resname,
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NameStr(att_tup->attname)) == 0);
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new_tle = process_matched_tle(old_tle, new_tle);
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if (old_tle->expr != NULL && IsA(old_tle->expr, SetToDefault))
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{
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/* Set to the default value of the column, as requested */
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Node *new_expr;
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new_expr = build_column_default(target_relation, attrno);
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new_tle = makeTargetEntry(makeResdom(attrno,
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att_tup->atttypid,
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att_tup->atttypmod,
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pstrdup(NameStr(att_tup->attname)),
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false),
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(Expr *) new_expr);
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}
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else
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/* Normal Case */
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new_tle = process_matched_tle(old_tle, new_tle);
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/* keep scanning to detect multiple assignments to attr */
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}
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}
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@ -7,7 +7,7 @@
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* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* $Id: nodes.h,v 1.141 2003/06/25 03:40:19 momjian Exp $
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* $Id: nodes.h,v 1.142 2003/06/25 04:19:24 momjian Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -277,7 +277,7 @@ typedef enum NodeTag
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T_PrivGrantee,
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T_FuncWithArgs,
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T_PrivTarget,
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T_InsertDefault,
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T_SetToDefault,
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T_CreateOpClassItem,
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T_CompositeTypeStmt,
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T_InhRelation,
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@ -7,7 +7,7 @@
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* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* $Id: parsenodes.h,v 1.239 2003/06/25 03:40:19 momjian Exp $
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* $Id: parsenodes.h,v 1.240 2003/06/25 04:19:24 momjian Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -279,10 +279,10 @@ typedef struct ResTarget
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/*
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* Empty node used as a marker for Default Columns
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*/
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typedef struct InsertDefault
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typedef struct SetToDefault
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{
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NodeTag type;
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} InsertDefault;
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} SetToDefault;
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/*
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* SortGroupBy - for ORDER BY clause
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Reference in New Issue
Block a user