Function SPI_gettypeid

src/backend/executor/spi.c:1335–1351

* Get the data type OID for a column. * * There's nothing similar for typmod and typcollation. The rare consumers * thereof should inspect the TupleDesc directly. */

 * thereof should inspect the TupleDesc directly.
 */
Oid
SPI_gettypeid(TupleDesc tupdesc, int fnumber)
{
	SPI_result = 0;

	if (fnumber > tupdesc->natts || fnumber == 0 ||
		fnumber <= FirstLowInvalidHeapAttributeNumber)
	{
		SPI_result = SPI_ERROR_NOATTRIBUTE;
		return InvalidOid;
	}

	if (fnumber > 0)
		return TupleDescAttr(tupdesc, fnumber - 1)->atttypid;
	else
		return (SystemAttributeDefinition(fnumber))->atttypid;
}

char *
SPI_getrelname(Relation rel)