在语句SELECT * FROM student WHERE s _name LIKE ‘%晓%' ;其中WHERE关键字表示的含义是()。
A. 条件
B. 在哪里
C. 模糊查询
D. 逻辑运算
查询tb_ book表中useno字段的记录,并去除重复值的是()。
A. SELECT DISTINCT userno FROM tb_ book;
B. SELECT userno DITINCT FROM tb_book;
C. SELECT DITINCT(userno) FROM tb_book;
D. SELECT userno FROM DISTINCT tb_book;
查询tb001数据表中的前5条记录,并升序排列,语法格式是( )。
A. SELECT * FROM tb001 WHERE ORDER BY id ASC LIMIT 0,5;
B. SELECT * FROM tb001 WHERE ORDER BY id DESC LIMIT 0,5;
C. SELECT * FROM tb001 WHERE ORDER BY id GROUP BY LIMIT 0,5;
D. SELECT * FROM tb001 WHERE ORDER BY id ORDER LIMIT 0,5;
SQL语言中,删除EMP表中全部数据的命令正确的是( )。
A. DELETE * FROM emp
B. DROP TABLE emp
C. TRUNCATE TABLE emp
D. 没有正确答案