Function dbms_sql_describe_columns

gpcontrib/orafce/dbms_sql.c:2110–2289

* CREATE PROCEDURE dbms_sql.describe_columns(c int, OUT col_cnt int, OUT desc_t dbms_sql.desc_rec[]) * * Returns an array of column's descriptions. Attention, the typid are related to PostgreSQL type * system. */

 * system.
 */
Datum
dbms_sql_describe_columns(PG_FUNCTION_ARGS)
{
	CursorData *c;
	Datum		values[13];
	bool		nulls[13];
	TupleDesc	tupdesc;
	TupleDesc	desc_rec_tupdesc;
	TupleDesc	cursor_tupdesc;
	HeapTuple	tuple;
	Oid			arraytypid;
	Oid			desc_rec_typid;
	Oid		   *types = NULL;
	ArrayBuildState *abuilder;
	SPIPlanPtr		plan;
	CachedPlanSource *plansource = NULL;
	int			ncolumns = 0;
	int			rc;
	int			i = 0;
	bool		nonatomic;
	MemoryContext callercxt = CurrentMemoryContext;

	if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
		elog(ERROR, "return type must be a row type");

	arraytypid = TupleDescAttr(tupdesc, 1)->atttypid;
	desc_rec_typid = get_element_type(arraytypid);

	if (!OidIsValid(desc_rec_typid))
		elog(ERROR, "second output field must be an array");

	desc_rec_tupdesc = lookup_rowtype_tupdesc_copy(desc_rec_typid, -1);

	abuilder = initArrayResult(desc_rec_typid, callercxt, true);

	c = get_cursor(fcinfo, true);

	if (c->variables)
	{
		ListCell *lc;

		types = palloc(sizeof(Oid) * c->nvariables);
		i = 0;

		foreach(lc, c->variables)
		{
			VariableData *var = (VariableData *) lfirst(lc);

			if (var->typoid == InvalidOid)
				ereport(ERROR,
					    (errcode(ERRCODE_UNDEFINED_PARAMETER),
					     errmsg("variable \"%s\" has not a value", var->refname)));

			types[i++] = var->is_array ? var->typelemid : var->typoid;
		}
	}

	/*