Function get_tle_by_resno

src/backend/parser/parse_relation.c:3690–3703

* Given a targetlist and a resno, return the matching TargetEntry * * Returns NULL if resno is not present in list. * * Note: we need to search, rather than just indexing with list_nth(), * because not all tlists are sorted by resno. */

 * because not all tlists are sorted by resno.
 */
TargetEntry *
get_tle_by_resno(List *tlist, AttrNumber resno)
{
	ListCell   *l;

	foreach(l, tlist)
	{
		TargetEntry *tle = (TargetEntry *) lfirst(l);

		if (tle->resno == resno)
			return tle;
	}
	return NULL;
}

/*
 * Given a Query and rangetable index, return relation's RowMarkClause if any