UNION operator must have an equal number of expressions

做SQL统计报表的时候，调试报错如下：

Msg 205, Level 16, State 1, Line 1

All queries combined using a UNION, INTERSECT or EXCEPT operator must have an equal number of expressions in their target lists.

说明：select *from table_A  union [all]  select *from table_B 

解决方案：联合查询union [all] 函数必须 table_A 与 table_B 的列字段数量一致 

比如table_A有5个字段，table_B有3个字段，使用union all会出现如上错误提示