Function addRangeTableEntryForCTE

src/backend/parser/parse_relation.c:2470–2613

* Add an entry for a CTE reference to the pstate's range table (p_rtable). * Then, construct and return a ParseNamespaceItem for the new RTE. * * This is much like addRangeTableEntry() except that it makes a CTE RTE. */

 * This is much like addRangeTableEntry() except that it makes a CTE RTE.
 */
ParseNamespaceItem *
addRangeTableEntryForCTE(ParseState *pstate,
						 CommonTableExpr *cte,
						 Index levelsup,
						 RangeVar *rv,
						 bool inFromCl)
{
	RangeTblEntry *rte = makeNode(RangeTblEntry);
	Alias	   *alias = rv->alias;
	char	   *refname = alias ? alias->aliasname : cte->ctename;
	Alias	   *eref;
	int			numaliases;
	int			varattno;
	ListCell   *lc;
	int			n_dontexpand_columns = 0;
	ParseNamespaceItem *psi;

	Assert(pstate != NULL);

	rte->rtekind = RTE_CTE;
	rte->ctename = cte->ctename;
	rte->ctelevelsup = levelsup;

	/* Self-reference if and only if CTE's parse analysis isn't completed */
	rte->self_reference = !IsA(cte->ctequery, Query);
	Assert(cte->cterecursive || !rte->self_reference);
	/* Bump the CTE's refcount if this isn't a self-reference */
	if (!rte->self_reference)
		cte->cterefcount++;

	/*
	 * We throw error if the CTE is INSERT/UPDATE/DELETE without RETURNING.
	 * This won't get checked in case of a self-reference, but that's OK
	 * because data-modifying CTEs aren't allowed to be recursive anyhow.
	 */
	if (IsA(cte->ctequery, Query))
	{
		Query	   *ctequery = (Query *) cte->ctequery;

		if (ctequery->commandType != CMD_SELECT &&
			ctequery->returningList == NIL)
			ereport(ERROR,
					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
					 errmsg("WITH query \"%s\" does not have a RETURNING clause",
							cte->ctename),
					 parser_errposition(pstate, rv->location)));
	}

	rte->coltypes = list_copy(cte->ctecoltypes);
	rte->coltypmods = list_copy(cte->ctecoltypmods);
	rte->colcollations = list_copy(cte->ctecolcollations);

	rte->alias = alias;
	if (alias)
		eref = copyObject(alias);
	else
		eref = makeAlias(refname, NIL);
	numaliases = list_length(eref->colnames);