• 2022-06-01
    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
  • C

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    内容

    • 0

      有SQL语句:SELECT * FROM 教师 WHERE NOT(工资>3000 OR 工资<2000),与如上语句等价的SQL语句是( ) A: SELECT * FROM 教师 WHERE 工资 BETWEEN 2000 AND 3000 B: SELECT * FROM 教师 WHERE 工资 >2000 AND 工资<3000> C: SELECT * FROM 教师 WHERE 工资>2000 OR 工资<3000> D: SELECT * FROM 教师 WHERE 工资< AND >=3000

    • 1

      要从SC表中查找缺成绩(SCORE)的学生学号(NO),相应的SQL语句是( )。 A: SELECT NO FROM SC WHERE SCORE = 0 B: SELECT NO FROM SC WHERE SCORE IS 'NULL' C: SELECT NO FROM SC WHERE SCORE = NULL D: SELECT NO FROM SC WHERE SCORE IS NULL

    • 2

      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;

    • 3

      在“教师”表中查找女教师的全部记录,正确的语句是()。 A: SELECT*FROM教师IF性别=“女” B: SELECT性别FROM教师IF性别=“女” C: SELECT*FROM教师WHERE性别=“女” D: SELECT教师FROM性别WHERE性别=“女”

    • 4

      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;