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UPDATE ... SET <col> = DEFAULT
Rod Taylor
1 parent a09ccc7 commit 53c4f12

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9 files changed

+90
-49
lines changed

9 files changed

+90
-49
lines changed

‎doc/src/sgml/ref/update.sgml

Lines changed: 11 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -1,5 +1,5 @@
11
<!--
2-
$Header: /cvsroot/pgsql/doc/src/sgml/ref/update.sgml,v 1.21 2003/04/26 23:56:51 petere Exp $
2+
$Header: /cvsroot/pgsql/doc/src/sgml/ref/update.sgml,v 1.22 2003/06/25 04:19:24 momjian Exp $
33
PostgreSQL documentation
44
-->
55

@@ -16,7 +16,7 @@ PostgreSQL documentation
1616

1717
<refsynopsisdiv>
1818
<synopsis>
19-
UPDATE [ ONLY ] <replaceable class="PARAMETER">table</replaceable> SET <replaceable class="PARAMETER">column</replaceable> = <replaceable class="PARAMETER">expression</replaceable> [, ...]
19+
UPDATE [ ONLY ] <replaceable class="PARAMETER">table</replaceable> SET <replaceable class="PARAMETER">column</replaceable> = { <replaceable class="PARAMETER">expression</replaceable> | DEFAULT } [, ...]
2020
[ FROM <replaceable class="PARAMETER">fromlist</replaceable> ]
2121
[ WHERE <replaceable class="PARAMETER">condition</replaceable> ]
2222
</synopsis>
@@ -77,6 +77,15 @@ UPDATE [ ONLY ] <replaceable class="PARAMETER">table</replaceable> SET <replacea
7777
</listitem>
7878
</varlistentry>
7979

80+
<varlistentry>
81+
<term><literal>DEFAULT</literal></term>
82+
<listitem>
83+
<para>
84+
This column will be filled with its default value.
85+
</para>
86+
</listitem>
87+
</varlistentry>
88+
8089
<varlistentry>
8190
<term><replaceable class="PARAMETER">fromlist</replaceable></term>
8291
<listitem>

‎src/backend/nodes/copyfuncs.c

Lines changed: 6 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -15,7 +15,7 @@
1515
* Portions Copyright (c) 1994, Regents of the University of California
1616
*
1717
* IDENTIFICATION
18-
* $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.254 2003/06/25 03:40:17 momjian Exp $
18+
* $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.255 2003/06/25 04:19:24 momjian Exp $
1919
*
2020
*-------------------------------------------------------------------------
2121
*/
@@ -1661,10 +1661,10 @@ _copyFuncWithArgs(FuncWithArgs *from)
16611661
return newnode;
16621662
}
16631663

1664-
static InsertDefault *
1665-
_copyInsertDefault(InsertDefault *from)
1664+
static SetToDefault *
1665+
_copySetToDefault(SetToDefault *from)
16661666
{
1667-
InsertDefault *newnode = makeNode(InsertDefault);
1667+
SetToDefault *newnode = makeNode(SetToDefault);
16681668

16691669
return newnode;
16701670
}
@@ -2942,8 +2942,8 @@ copyObject(void *from)
29422942
case T_FuncWithArgs:
29432943
retval = _copyFuncWithArgs(from);
29442944
break;
2945-
case T_InsertDefault:
2946-
retval = _copyInsertDefault(from);
2945+
case T_SetToDefault:
2946+
retval = _copySetToDefault(from);
29472947
break;
29482948

29492949
default:

‎src/backend/nodes/equalfuncs.c

Lines changed: 4 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -18,7 +18,7 @@
1818
* Portions Copyright (c) 1994, Regents of the University of California
1919
*
2020
* IDENTIFICATION
21-
* $Header: /cvsroot/pgsql/src/backend/nodes/equalfuncs.c,v 1.197 2003/06/25 03:40:17 momjian Exp $
21+
* $Header: /cvsroot/pgsql/src/backend/nodes/equalfuncs.c,v 1.198 2003/06/25 04:19:24 momjian Exp $
2222
*
2323
*-------------------------------------------------------------------------
2424
*/
@@ -728,7 +728,7 @@ _equalFuncWithArgs(FuncWithArgs *a, FuncWithArgs *b)
728728
}
729729

730730
static bool
731-
_equalInsertDefault(InsertDefault *a, InsertDefault *b)
731+
_equalSetToDefault(SetToDefault *a, SetToDefault *b)
732732
{
733733
return true;
734734
}
@@ -2055,8 +2055,8 @@ equal(void *a, void *b)
20552055
case T_FuncWithArgs:
20562056
retval = _equalFuncWithArgs(a, b);
20572057
break;
2058-
case T_InsertDefault:
2059-
retval = _equalInsertDefault(a, b);
2058+
case T_SetToDefault:
2059+
retval = _equalSetToDefault(a, b);
20602060
break;
20612061

20622062
default:

‎src/backend/parser/analyze.c

Lines changed: 6 additions & 18 deletions
Original file line numberDiff line numberDiff line change
@@ -6,7 +6,7 @@
66
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
77
* Portions Copyright (c) 1994, Regents of the University of California
88
*
9-
* $Header: /cvsroot/pgsql/src/backend/parser/analyze.c,v 1.276 2003/06/25 03:40:17 momjian Exp $
9+
* $Header: /cvsroot/pgsql/src/backend/parser/analyze.c,v 1.277 2003/06/25 04:19:24 momjian Exp $
1010
*
1111
*-------------------------------------------------------------------------
1212
*/
@@ -660,23 +660,9 @@ transformInsertStmt(ParseState *pstate, InsertStmt *stmt,
660660
col = (ResTarget *) lfirst(icolumns);
661661
Assert(IsA(col, ResTarget));
662662

663-
/*
664-
* When the value is to be set to the column default we can simply
665-
* drop the TLE now and handle it later on using methods for missing
666-
* columns.
667-
*/
668-
if (IsA(tle, InsertDefault))
669-
{
670-
qry->targetList = lremove(tle, qry->targetList);
671-
/* Note: the stmt->cols list is not adjusted to match */
672-
}
673-
else
674-
{
675-
/* Normal case */
676-
Assert(!tle->resdom->resjunk);
677-
updateTargetListEntry(pstate, tle, col->name, lfirsti(attnos),
678-
col->indirection);
679-
}
663+
Assert(!tle->resdom->resjunk);
664+
updateTargetListEntry(pstate, tle, col->name, lfirsti(attnos),
665+
col->indirection);
680666

681667
icolumns = lnext(icolumns);
682668
attnos = lnext(attnos);
@@ -2431,10 +2417,12 @@ transformUpdateStmt(ParseState *pstate, UpdateStmt *stmt)
24312417
if (origTargetList == NIL)
24322418
elog(ERROR, "UPDATE target count mismatch --- internal error");
24332419
origTarget = (ResTarget *) lfirst(origTargetList);
2420+
24342421
updateTargetListEntry(pstate, tle, origTarget->name,
24352422
attnameAttNum(pstate->p_target_relation,
24362423
origTarget->name, true),
24372424
origTarget->indirection);
2425+
24382426
origTargetList = lnext(origTargetList);
24392427
}
24402428
if (origTargetList != NIL)

‎src/backend/parser/gram.y

Lines changed: 11 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -11,7 +11,7 @@
1111
*
1212
*
1313
* IDENTIFICATION
14-
* $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.419 2003/06/25 03:40:18 momjian Exp $
14+
* $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.420 2003/06/25 04:19:24 momjian Exp $
1515
*
1616
* HISTORY
1717
* AUTHOR DATE MAJOR EVENT
@@ -6945,6 +6945,15 @@ update_target_el:
69456945
$$->indirection = $2;
69466946
$$->val = (Node *)$4;
69476947
}
6948+
| ColId opt_indirection '=' DEFAULT
6949+
{
6950+
SetToDefault *def = makeNode(SetToDefault);
6951+
$$ = makeNode(ResTarget);
6952+
$$->name = $1;
6953+
$$->indirection = NULL;
6954+
$$->val = (Node *)def;
6955+
}
6956+
69486957
;
69496958

69506959
insert_target_list:
@@ -6956,7 +6965,7 @@ insert_target_el:
69566965
target_el { $$ = $1; }
69576966
| DEFAULT
69586967
{
6959-
InsertDefault *def = makeNode(InsertDefault);
6968+
SetToDefault *def = makeNode(SetToDefault);
69606969
$$ = makeNode(ResTarget);
69616970
$$->name = NULL;
69626971
$$->indirection = NULL;

‎src/backend/parser/parse_target.c

Lines changed: 27 additions & 10 deletions
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
*
99
*
1010
* IDENTIFICATION
11-
* $Header: /cvsroot/pgsql/src/backend/parser/parse_target.c,v 1.102 2003/05/31 19:03:34 tgl Exp $
11+
* $Header: /cvsroot/pgsql/src/backend/parser/parse_target.c,v 1.103 2003/06/25 04:19:24 momjian Exp $
1212
*
1313
*-------------------------------------------------------------------------
1414
*/
@@ -177,19 +177,24 @@ transformTargetList(ParseState *pstate, List *targetlist)
177177
false));
178178
}
179179
}
180-
else if (IsA(res->val, InsertDefault))
180+
else if (IsA(res->val, SetToDefault))
181181
{
182-
InsertDefault *newnode = makeNode(InsertDefault);
183-
184182
/*
185-
* If this is a DEFAULT element, we make a junk entry which
186-
* will get dropped on return to transformInsertStmt().
183+
* If this is a DEFAULT element, we make a standard entry using
184+
* the default for the target expression. rewriteTargetList will
185+
* substitute the columns default for this expression.
187186
*/
188-
p_target = lappend(p_target, newnode);
187+
p_target = lappend(p_target,
188+
makeTargetEntry(makeResdom((AttrNumber) pstate->p_next_resno++,
189+
UNKNOWNOID,
190+
-1,
191+
res->name,
192+
false),
193+
(Expr *) res->val));
189194
}
190195
else
191196
{
192-
/* Everything else but ColumnRef and InsertDefault */
197+
/* Everything else but ColumnRef and SetToDefault */
193198
p_target = lappend(p_target,
194199
transformTargetEntry(pstate,
195200
res->val,
@@ -321,9 +326,10 @@ updateTargetListEntry(ParseState *pstate,
321326
int attrno,
322327
List *indirection)
323328
{
324-
Oid type_id = exprType((Node *) tle->expr); /* type of value provided */
329+
Oid type_id; /* type of value provided */
325330
Oid attrtype; /* type of target column */
326331
int32 attrtypmod;
332+
bool isDefault = false;
327333
Resdom *resnode = tle->resdom;
328334
Relation rd = pstate->p_target_relation;
329335

@@ -333,6 +339,17 @@ updateTargetListEntry(ParseState *pstate,
333339
attrtype = attnumTypeId(rd, attrno);
334340
attrtypmod = rd->rd_att->attrs[attrno - 1]->atttypmod;
335341

342+
/* The type of the default column is equivalent to that of the column */
343+
if (tle->expr != NULL && IsA(tle->expr, SetToDefault))
344+
{
345+
type_id = attrtype;
346+
isDefault = true;
347+
}
348+
349+
/* Otherwise the expression holds the type */
350+
else
351+
type_id = exprType((Node *) tle->expr);
352+
336353
/*
337354
* If there are subscripts on the target column, prepare an array
338355
* assignment expression. This will generate an array value that the
@@ -383,7 +400,7 @@ updateTargetListEntry(ParseState *pstate,
383400
* coercion. But accept InvalidOid, which indicates the source is
384401
* a NULL constant. (XXX is that still true?)
385402
*/
386-
if (type_id != InvalidOid)
403+
if (!isDefault && type_id != InvalidOid)
387404
{
388405
tle->expr = (Expr *)
389406
coerce_to_target_type(pstate,

‎src/backend/rewrite/rewriteHandler.c

Lines changed: 20 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -7,7 +7,7 @@
77
* Portions Copyright (c) 1994, Regents of the University of California
88
*
99
* IDENTIFICATION
10-
* $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteHandler.c,v 1.120 2003/05/02 20:54:35 tgl Exp $
10+
* $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteHandler.c,v 1.121 2003/06/25 04:19:24 momjian Exp $
1111
*
1212
*-------------------------------------------------------------------------
1313
*/
@@ -307,7 +307,25 @@ rewriteTargetList(Query *parsetree, Relation target_relation)
307307
{
308308
Assert(strcmp(resdom->resname,
309309
NameStr(att_tup->attname)) == 0);
310-
new_tle = process_matched_tle(old_tle, new_tle);
310+
311+
if (old_tle->expr != NULL && IsA(old_tle->expr, SetToDefault))
312+
{
313+
/* Set to the default value of the column, as requested */
314+
Node *new_expr;
315+
316+
new_expr = build_column_default(target_relation, attrno);
317+
318+
new_tle = makeTargetEntry(makeResdom(attrno,
319+
att_tup->atttypid,
320+
att_tup->atttypmod,
321+
pstrdup(NameStr(att_tup->attname)),
322+
false),
323+
(Expr *) new_expr);
324+
}
325+
else
326+
/* Normal Case */
327+
new_tle = process_matched_tle(old_tle, new_tle);
328+
311329
/* keep scanning to detect multiple assignments to attr */
312330
}
313331
}

‎src/include/nodes/nodes.h

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -7,7 +7,7 @@
77
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
88
* Portions Copyright (c) 1994, Regents of the University of California
99
*
10-
* $Id: nodes.h,v 1.141 2003/06/25 03:40:19 momjian Exp $
10+
* $Id: nodes.h,v 1.142 2003/06/25 04:19:24 momjian Exp $
1111
*
1212
*-------------------------------------------------------------------------
1313
*/
@@ -277,7 +277,7 @@ typedef enum NodeTag
277277
T_PrivGrantee,
278278
T_FuncWithArgs,
279279
T_PrivTarget,
280-
T_InsertDefault,
280+
T_SetToDefault,
281281
T_CreateOpClassItem,
282282
T_CompositeTypeStmt,
283283
T_InhRelation,

‎src/include/nodes/parsenodes.h

Lines changed: 3 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -7,7 +7,7 @@
77
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
88
* Portions Copyright (c) 1994, Regents of the University of California
99
*
10-
* $Id: parsenodes.h,v 1.239 2003/06/25 03:40:19 momjian Exp $
10+
* $Id: parsenodes.h,v 1.240 2003/06/25 04:19:24 momjian Exp $
1111
*
1212
*-------------------------------------------------------------------------
1313
*/
@@ -279,10 +279,10 @@ typedef struct ResTarget
279279
/*
280280
* Empty node used as a marker for Default Columns
281281
*/
282-
typedef struct InsertDefault
282+
typedef struct SetToDefault
283283
{
284284
NodeTag type;
285-
} InsertDefault;
285+
} SetToDefault;
286286

287287
/*
288288
* SortGroupBy - for ORDER BY clause

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