SELECT语句中实现空值查询应使用=NULL。
举一反三
- 在SELECT语句中,表示空值NULL的语句是()。 A: =’’ B: =NULL C: isNULL D: =0
- 在某SELECT语句的WHERE子句中,需要对Grade列的空值进行处理。下列关于空值的操作错误的是( )。 A: Grade Is Not NULL B: Grade Is NULL C: Grade=NULL D: NOT ( Grade IS NULL )
- 设在某SELECT语句的WHERE子句中,需要对Grade列的空值进行处理。下列关于空值的操作中,错误的是() A: A.Grade IS not null B: B.Grade IS null C: C.Grade = null D: D.Not(Grade IS null)
- 若想查询student表中name为空值的记录,则正确的SQL语句是( )。 A: SELECT * FROM student WHERE name = NULL; B: SELECT * FROM student WHERE name like NULL; C: SELECT * FROM student WHERE name = 'NULL'; D: SELECT * FROM student WHERE name is NULL;
- 若想查询student表中name为空值的记录,则正确的SQL语句是(1.0分) A: select * from student where name = null; B: select * from student where name link null; C: select * from student where name = 'null'; D: select * from student where name is null;