mysql - 这两个mysql操作符有什么区别

Question

谁能告诉我这两个 mysql 运算符有什么区别:-

<=> 和 =

两者都得到相同的结果。它们在使用上是否相同。

select s.dwt,s.shipnam from tbl_ship s
where s.dwt >= 1 and s.deleted = 'N'
and s.dwt = 11000
group by s.co_cod

和

select s.dwt,s.shipnam from tbl_ship s
where s.dwt >= 1 and s.deleted = 'N'
and s.dwt <=> 11000
group by s.co_cod

谢谢。

Answer 1

<=>是NULL-safe equal to operator .