Function UtilityTupleDescriptor

src/backend/tcop/utility.c:2756–2808

* UtilityTupleDescriptor * Fetch the actual output tuple descriptor for a utility statement * for which UtilityReturnsTuples() previously returned "true". * * The returned descriptor is created in (or copied into) the current memory * context. */

 * context.
 */
TupleDesc
UtilityTupleDescriptor(Node *parsetree)
{
	switch (nodeTag(parsetree))
	{
		case T_CallStmt:
			return CallStmtResultDesc((CallStmt *) parsetree);

		case T_FetchStmt:
			{
				FetchStmt  *stmt = (FetchStmt *) parsetree;
				Portal		portal;

				if (stmt->ismove)
					return NULL;
				portal = GetPortalByName(stmt->portalname);
				if (!PortalIsValid(portal))
					return NULL;	/* not our business to raise error */
				return CreateTupleDescCopy(portal->tupDesc);
			}

		case T_ExecuteStmt:
			{
				ExecuteStmt *stmt = (ExecuteStmt *) parsetree;
				PreparedStatement *entry;

				entry = FetchPreparedStatement(stmt->name, false);
				if (!entry)
					return NULL;	/* not our business to raise error */
				return FetchPreparedStatementResultDesc(entry);
			}

		case T_ExplainStmt:
			return ExplainResultDesc((ExplainStmt *) parsetree);

		case T_VariableShowStmt:
			{
				VariableShowStmt *n = (VariableShowStmt *) parsetree;

				return GetPGVariableResultDesc(n->name);
			}

		case T_RetrieveStmt:
			{
				RetrieveStmt *n = (RetrieveStmt *) parsetree;

				return CreateTupleDescCopy(GetRetrieveStmtTupleDesc(n));
			}

		default:
			return NULL;
	}
}


/*