Re: Bug #896: Column Constraint Not Working in ALTER TABLE ADD COLUMN?

pgsql-bugs(at)postgresql(dot)org writes:
> Column Constraint Not Working in ALTER TABLE ADD COLUMN?

Yeah, the parser was losing foreign key constraints in this case :-(
Patch against 7.3 is attached.

regards, tom lane

*** src/backend/parser/analyze.c.orig Mon Feb 10 23:13:39 2003
--- src/backend/parser/analyze.c Thu Feb 13 17:41:13 2003
***************
*** 111,117 ****
static void transformIndexConstraints(ParseState *pstate,
CreateStmtContext *cxt);
static void transformFKConstraints(ParseState *pstate,
! CreateStmtContext *cxt);
static void applyColumnNames(List *dst, List *src);
static List *getSetColTypes(ParseState *pstate, Node *node);
static void transformForUpdate(Query *qry, List *forUpdate);
--- 111,118 ----
static void transformIndexConstraints(ParseState *pstate,
CreateStmtContext *cxt);
static void transformFKConstraints(ParseState *pstate,
! CreateStmtContext *cxt,
! bool isAddConstraint);
static void applyColumnNames(List *dst, List *src);
static List *getSetColTypes(ParseState *pstate, Node *node);
static void transformForUpdate(Query *qry, List *forUpdate);
***************
*** 770,776 ****
/*
* Postprocess foreign-key constraints.
*/
! transformFKConstraints(pstate, &cxt);

/*
* Output results.
--- 771,777 ----
/*
* Postprocess foreign-key constraints.
*/
! transformFKConstraints(pstate, &cxt, false);

/*
* Output results.
***************
*** 1296,1302 ****
}

static void
! transformFKConstraints(ParseState *pstate, CreateStmtContext *cxt)
{
if (cxt->fkconstraints == NIL)
return;
--- 1297,1304 ----
}

static void
! transformFKConstraints(ParseState *pstate, CreateStmtContext *cxt,
! bool isAddConstraint)
{
if (cxt->fkconstraints == NIL)
return;
***************
*** 1305,1320 ****
cxt->stmtType);

/*
! * For ALTER TABLE ADD CONSTRAINT, nothing to do. For CREATE TABLE,
! * gin up an ALTER TABLE ADD CONSTRAINT command to execute after
! * the basic CREATE TABLE is complete.
*
* Note: the ADD CONSTRAINT command must also execute after any index
* creation commands. Thus, this should run after
* transformIndexConstraints, so that the CREATE INDEX commands are
* already in cxt->alist.
*/
! if (strcmp(cxt->stmtType, "CREATE TABLE") == 0)
{
AlterTableStmt *alterstmt = makeNode(AlterTableStmt);
List *fkclist;
--- 1307,1322 ----
cxt->stmtType);

/*
! * For ALTER TABLE ADD CONSTRAINT, nothing to do. For CREATE TABLE or
! * ALTER TABLE ADD COLUMN, gin up an ALTER TABLE ADD CONSTRAINT command
! * to execute after the basic command is complete.
*
* Note: the ADD CONSTRAINT command must also execute after any index
* creation commands. Thus, this should run after
* transformIndexConstraints, so that the CREATE INDEX commands are
* already in cxt->alist.
*/
! if (!isAddConstraint)
{
AlterTableStmt *alterstmt = makeNode(AlterTableStmt);
List *fkclist;
***************
*** 2253,2259 ****
(ColumnDef *) stmt->def);

transformIndexConstraints(pstate, &cxt);
! transformFKConstraints(pstate, &cxt);

((ColumnDef *) stmt->def)->constraints = cxt.ckconstraints;
*extras_before = nconc(*extras_before, cxt.blist);
--- 2255,2261 ----
(ColumnDef *) stmt->def);

transformIndexConstraints(pstate, &cxt);
! transformFKConstraints(pstate, &cxt, false);

((ColumnDef *) stmt->def)->constraints = cxt.ckconstraints;
*extras_before = nconc(*extras_before, cxt.blist);
***************
*** 2290,2298 ****
elog(ERROR, "Unexpected node type in ALTER TABLE ADD CONSTRAINT");

transformIndexConstraints(pstate, &cxt);
! transformFKConstraints(pstate, &cxt);

Assert(cxt.columns == NIL);
stmt->def = (Node *) nconc(cxt.ckconstraints, cxt.fkconstraints);
*extras_before = nconc(*extras_before, cxt.blist);
*extras_after = nconc(cxt.alist, *extras_after);
--- 2292,2301 ----
elog(ERROR, "Unexpected node type in ALTER TABLE ADD CONSTRAINT");

transformIndexConstraints(pstate, &cxt);
! transformFKConstraints(pstate, &cxt, true);

Assert(cxt.columns == NIL);
+ /* fkconstraints should be put into my own stmt in this case */
stmt->def = (Node *) nconc(cxt.ckconstraints, cxt.fkconstraints);
*extras_before = nconc(*extras_before, cxt.blist);
*extras_after = nconc(cxt.alist, *extras_after);