Function SPIReturnDatum

pg_documentdb/src/utils/query_utils.c:318–339

* SPIReturnDatum copies first datum of the first tuple returned to SPI * by the last query that has been executed into current memory context and * returns that datum. * * Returns NULL if query returned nothing at all or if the returned datum * itself is NULL. * * Note: position is 1-based index. */

 * Note: position is 1-based index.
 */
static Datum
SPIReturnDatum(bool *isNull, int position)
{
	*isNull = true;

	Datum retDatum = 0;
	if (SPI_processed >= 1 && SPI_tuptable && SPI_tuptable->tupdesc->natts >= position)
	{
		int tupleNumber = 0;
		AttrNumber attrNumber = position;
		Datum resultDatum = SPI_getbinval(SPI_tuptable->vals[tupleNumber],
										  SPI_tuptable->tupdesc, attrNumber, isNull);
		if (!*isNull)
		{
			/* copy datum into original memory context */
			Form_pg_attribute attr = TupleDescAttr(SPI_tuptable->tupdesc, attrNumber - 1);
			retDatum = SPI_datumTransfer(resultDatum, attr->attbyval, attr->attlen);
		}
	}

	return retDatum;
}


/*