• 2022-05-28
    阅读下面的SQL语句: SELECT DISTINCT name,gender FROM student; 关于此SQL语句的描述,正确的是
  • 查询student表中name和gender记录,并保证没有重复记录

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    • 0

      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;

    • 1

      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;

    • 2

      阅读下面的SQL语句:select * from user where firstname=张; 下列选项中,对于上述SQL语句解释正确的是

    • 3

      假设student表中共有9条记录,而存在name与gender值完全相同的记录有3条,那么使用 SELECT DISTINCT name,gender FROM student;语句查询出的记录条数是

    • 4

      在 SQL 语句“select * from student”中,“*”号的含义是