A. select * from emp; B. select ename,hiredate,sal from emp; C. select * from emp order deptno; D. select * from where deptno=1
A. MAX B. IF CASE D. AVG
A. COUNT B. MAX C. AVG D. SUM
A. ORDER BY B. ORDERED BY C. GROUP BY D. GROUPED BY
A. 嵌套在查询命令FROM子句中的查询语句 B. 为了与父查询区别,子查询必须用引号括起来 C. 子查询只能是单表查询 D. 嵌入到另一个查询语句之中的查询语句