Function validateDomainConstraint

src/backend/commands/typecmds.c:3253–3340

}

static void
validateDomainConstraint(Oid domainoid, char *ccbin)
{
	Expr	   *expr = (Expr *) stringToNode(ccbin);
	List	   *rels;
	ListCell   *rt;
	EState	   *estate;
	ExprContext *econtext;
	ExprState  *exprstate;

	/* Need an EState to run ExecEvalExpr */
	estate = CreateExecutorState();
	econtext = GetPerTupleExprContext(estate);

	/* build execution state for expr */
	exprstate = ExecPrepareExpr(expr, estate);

	/* Fetch relation list with attributes based on this domain */
	/* ShareLock is sufficient to prevent concurrent data changes */

	rels = get_rels_with_domain(domainoid, ShareLock);

	foreach(rt, rels)
	{
		RelToCheck *rtc = (RelToCheck *) lfirst(rt);
		Relation	testrel = rtc->rel;
		TupleDesc	tupdesc = RelationGetDescr(testrel);
		TupleTableSlot *slot;
		TableScanDesc scan;
		Snapshot	snapshot;

		/* Scan all tuples in this relation */
		snapshot = RegisterSnapshot(GetLatestSnapshot());
		scan = table_beginscan(testrel, snapshot, 0, NULL);
		slot = table_slot_create(testrel, NULL);
		while (table_scan_getnextslot(scan, ForwardScanDirection, slot))
		{
			int			i;

			/* Test attributes that are of the domain */
			for (i = 0; i < rtc->natts; i++)
			{
				int			attnum = rtc->atts[i];
				Datum		d;
				bool		isNull;
				Datum		conResult;
				Form_pg_attribute attr = TupleDescAttr(tupdesc, attnum - 1);

				d = slot_getattr(slot, attnum, &isNull);

				econtext->domainValue_datum = d;
				econtext->domainValue_isNull = isNull;

				conResult = ExecEvalExprSwitchContext(exprstate,
													  econtext,
													  &isNull);

				if (!isNull && !DatumGetBool(conResult))