A. 对 B. 错
A. DDL B. DQL C. DML DCL
A. 算术运算符 B. 赋值运算符 C. 比较运算符 D. 逻辑运算符
A. SHOW DATABASE; B. CREATE myschool; C. USEDATABASEmyschool; DROP DATABASEmyschool;
A. SIGNED B. UNSIGNED C. SIGN D. UNSIGN