判断字段是否为null
select * from table where c is null
select * from table where c is not null
判断字段是否为空
select * from table where c=''
select * from talbe where c<>''
判断字段是否为null
select * from table where c is null
select * from table where c is not null
判断字段是否为空
select * from table where c=''
select * from talbe where c<>''
本站转载的文章为个人学习借鉴使用,本站对版权不负任何法律责任。如果侵犯了您的隐私权益,请联系本站邮箱yoyou2525@163.com删除。