查询部门20的员工数量,每个月的工资总和及平均工资( )
A: SELECT sum(nvl(sal,0)),avg(nvl(sal,0)) from emp
B: SELECT ename,sum(nvl(sal,0)),avg(nvl(sal,0)) from emp where deptno =20 group by deptno
C: SELECT ename,count(empno),sum(nvl(sal,0)),avg(nvl(sal,0)) from emp where deptno =20 group by deptno
D: SELECT count(empno),sum(nvl(sal,0)),avg(nvl(sal,0)) from emp where deptno =20 group by deptno
A: SELECT sum(nvl(sal,0)),avg(nvl(sal,0)) from emp
B: SELECT ename,sum(nvl(sal,0)),avg(nvl(sal,0)) from emp where deptno =20 group by deptno
C: SELECT ename,count(empno),sum(nvl(sal,0)),avg(nvl(sal,0)) from emp where deptno =20 group by deptno
D: SELECT count(empno),sum(nvl(sal,0)),avg(nvl(sal,0)) from emp where deptno =20 group by deptno
举一反三
- 以下语句不正确的是( ) A: select * from emp B: select ename,hiredate,sal from emp C: select * from emp order deptno D: select * from where deptno=1 and sal<300
- 以下语句不正确的是( ) A: select * from emp; B: select ename,hiredate,sal from emp; C: select * from emp order deptno; D: select * from where deptno=1
- 以下语句正确的是() A: select<br/>sal+1 from emp; B: select<br/>sal*10,sal*deptno from emp; C: 不能使用运算符号 D: select<br/>sal*10,deptno*10 from emp;
- 统计每个部门中人数的语句是？ A: select count(id) from emp order by deptno; B: select sum(id) from emp order by deptno; C: select count(id) from emp group by deptno; D: select sum(id) from emp group by deptno;
- 智慧职教: 表结构如下：dept（deptno,dname）,emp(empno,ename,job,hiredate,sal，deptno)。创建视图查询系部名称、教师姓名，职位，工资信息。