题目:查询成绩不为空值的学生的信息,语法命令为()
select * from sc where grade is not null
select * from sc where grade!=null
select * from sc where grade is not ‘’
select * from sc where grade!=’’
题目:查询成绩不为空值的学生的信息,语法命令为()
select * from sc where grade is not null
select * from sc where grade!=null
select * from sc where grade is not ‘’
select * from sc where grade!=’’