执行以下查询，表头的显示为：( )
select sal 'Employee Salary' from emp;
select sal 'Employee Salary' from emp;
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;
- 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
- 设有职工基本表：EMP(ENO，ENAME，AGE，SEX，SALARY)，其属性分别表示职工号、姓名、年龄、性别、工资。为每个工资低于平均工资的女职工加薪200元，以下SQL语句正确的是______。 A: UPDATE EMP SET SALARY=SALARY+200 B: WHERE SALAEY＜(SELECT AVG(SALARY)FROM EMP) AND SEX=’女’ C: UPDATE FROM EMP SET SALARY=200 D: WHERE SALAEY＜(SELECT SUM(SALARY)FROM EMP)AND SEX=’女’ E: UPDATE EMP SET SALARY=200 F: WHERE SALAEY＜(SELECT AVG(SALARY)FROM EMP)AND SEX=’女’ G: UPDATE FROM EMP SET SALARY=SALARY+200 H: WHERE SALAEY＜(SELECT SUM(SALARY)FROM EMP)AND SEX=’女’
- 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