如何在plsql中检查列值是否为null？

Question

我有一个名称Shipment有列的表HAWB, MAWB.如何检查这两列是否具有空值？

Answer 1

要查找HAWBnull 为的行:

SELECT * FROM Shipment WHERE HAWB IS NULL;

要查找MAWBnull 为的行:

SELECT * FROM Shipment WHERE MAWB IS NULL;

如果要查找HAWB不为null 的行:

SELECT * FROM Shipment WHERE HAWB IS NOT NULL;

最后,如果要查找MAWB不为null 的行:

SELECT * FROM Shipment WHERE MAWB IS NOT NULL;