我希望仅在以下情况下显示一个区域
SELECT * FROM REI_LABOUR_RATE_REQUEST
WHERE BILLING_PARTNER = :P6_FILTER_DEALER
返回至少一行并且元素 :P6_FILTER_YEAR 不为 NULL。我通过写来尝试:
SELECT * FROM REI_LABOUR_RATE_REQUEST
WHERE BILLING_PARTNER = :P6_FILTER_DEALER
AND :P6_FILTER_YEAR != NULL;
但不知何故永远不会返回任何行。