Function SPI_getvalue

src/backend/executor/spi.c:1247–1277

}

char *
SPI_getvalue(HeapTuple tuple, TupleDesc tupdesc, int fnumber)
{
	Datum		val;
	bool		isnull;
	Oid			typoid,
				foutoid;
	bool		typisvarlena;

	SPI_result = 0;

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

	val = heap_getattr(tuple, fnumber, tupdesc, &isnull);
	if (isnull)
		return NULL;

	if (fnumber > 0)
		typoid = TupleDescAttr(tupdesc, fnumber - 1)->atttypid;
	else
		typoid = (SystemAttributeDefinition(fnumber))->atttypid;

	getTypeOutputInfo(typoid, &foutoid, &typisvarlena);

	return OidOutputFunctionCall(foutoid, val);
}

Datum
SPI_getbinval(HeapTuple tuple, TupleDesc tupdesc, int fnumber, bool *isnull)