小编Vhs*_*ros的帖子

你能帮我吗，我需要了解两者之间的区别

select * from table where field <> NULL;

和

select * from table where field is not NULL;

看看

SELECT COUNT(*) where (1 = null) -- return 0
SELECT COUNT(*) where (1 <> null) -- return 0
SELECT COUNT(*) where (1 is not  null) -- return 1
SELECT COUNT(*) where (null = null) -- return 0
SELECT COUNT(*) where (null <> null) -- return 0
SELECT COUNT(*) where (null is null) -- return 1
SELECT COUNT(*) where (null is …