• 2022-06-07
    下列( )赋值语句是错误的
    A: Select @c=1
    B: Set @c=1
    C: Select @dj=单价 from book order by 单价 desc
    D: Set @dj=单价 from book order by 单价 desc
  • D

    举一反三

    内容

    • 0

      下面在sh_goods表中根据cat_id升序排序,当cat_id相同时按price降序排序的语句是()。 A: SELECT * FROM sh_goods ORDER BY price DESC,cat_id; B: SELECT * FROM sh_goods ORDER BY price ,cat_id; C: SELECT * FROM sh_goods ORDER BY cat_id DESC,price; D: SELECT * FROM sh_goods ORDER BY cat_id,price DESC;

    • 1

      下列选项中,能够按照 score 由高到低显示 student 表中记录的 SQL 语句是 A: SELECT* FROM student ORDER BY score ; B: SELECT* FROM student ORDER BY score ASC ; C: SELECT * FROM student ORDER BY score DESC ; D: SELECT* FROM student GROUP BY score DESC ;

    • 2

      下面在sh_goods表中根据cat_id升序排序,并对每个cat_id按price降序排序的语句是( )。[br][/br](1.0) A: SELECT * FROM sh_goods ORDER BY price DESC,cat_id; B: SELECT * FROM sh_goods ORDER BY cat_id,price DESC; C: SELECT * FROM sh_goods ORDER BY price ,cat_id; D: SELECT * FROM sh_goods ORDER BY cat_id DESC,price;

    • 3

      ​下列语句用来删除数据表中指定记录,正确的语句是( )。‍ A: DELETE FROM book WHERE 单价>20 B: DELETE * FROM book C: DELETE FROM book HAVING 单价>20 D: DELETE FROM book

    • 4

      通过 SQL,您如何根据 "FirstName" 列降序地从 "Persons" 表返回所有记录? A: SELECT * FROM Persons SORT 'FirstName' DESC B: SELECT * FROM Persons ORDER BY FirstName DESC C: SELECT * FROM Persons ORDER FirstName DESC D: SELECT * FROM Persons SORT BY 'FirstName' DESC