A. drop database 数据库名 B. create database 数据库名 C. alter database 数据库名 D. show database数据库名
A. index普通索引 B. primary key主键索引 C. unique 唯一索引 D. count统计索引
A. order by B. where C. limit D. group by
A. ('201009','111',60,'必修') B. ('200823','101',NULL,NULL) C. (NULL,'103',80,'选修') D. ('201132',NULL,86,'101')
A. DB B. DBMS C. DBS DML