在Oracle中，有一个教师表teacher的结构如下： 下面哪个语句显示没有Email地址的教师的姓名（）。
A: select name from teacher where email=null
B: select name from teacher where email<>null
C: select name from teacher where email is null
D: select name from teacher where email is not null
A: select name from teacher where email=null
B: select name from teacher where email<>null
C: select name from teacher where email is null
D: select name from teacher where email is not null
举一反三
- 下面哪一个语句,显示没有Email地址的教师姓名() A: Select name from teacher where email=NULL; B: Select name from teacher where email C: Select name from teacher where email is NULL; D: Select name from teacher where emailis not NULL;
- 查询student表中的所有非空email信息, 以下语句正确的是（ ） A: Select email from student where email !=null B: Select email from student where email not is null C: Select email from student where email <> null D: Select email from student where email is not 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;
- 若在教师表中查找还没有输入工龄的记录,使用的SQL语句为 A: SELECT * FROM 教师 WHERE 工龄IS NOT NULL B: SELECT * FROM 教师 WHERE 工龄=0 C: SELECT * FROM 教师 WHERE 工龄 IS NULL D: SELECT * FROM 教师 WHERE 工龄=NULL