select * from table where a is not null 会把有内容的和内容为空的都查出来而select * from table where a != '' 只会把有内容的查出来 相关文章: 2022-12-23 2022-12-23 2021-09-21 2022-12-23 2022-12-23 2022-12-23 2021-11-23