UNION ALL 莫名其妙的给本来为null的字段赋值了

举个例子

select

A

B

C

from

(a as A

b as B

c as C)

UNION ALL 

(a as A

c as C

b as B)

因为前后顺序不同,B可能会被赋值c或b

posted @ 2022-05-27 15:21  蓝海的bug本  阅读(105)  评论(0编辑  收藏  举报