• 2022-06-01
     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
  • C

    内容

    • 0

      以下哪个查询操作能够实现将员工的参加工作日期按如下格式显示:月份/年份。 A: select ename,hiredate,to_char(hiredate,'HH/RR') from emp; B: select ename,hiredate,to_char(hiredate,'MM/RR') from emp; C: select ename,hiredate,to_char(hiredate,'MON') from emp; D: select ename,hiredate,to_char(hiredate,'DD/YY') from emp;

    • 1

      查询员工表emp中的第3条到第8条记录。显示emp表中的全部字段。( ) A: select rownum rn,emp.* from emp where rownum3; B: select * from(select rownum RN,emp.* from emp where RN3; C: select * from(select rownum RN,emp.* from emp where rownum3; D: select rownum RN,emp.* from emp where RN3;

    • 2

      执行以下查询,表头的显示为:( ) select sal 'Employee Salary' from emp;

    • 3

      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’

    • 4

      列出所有部门的部门名称和部门员工人数。如果部门没有员工,人数显示为0。正确的查询语句有_________。 A: SELECT dname,COUNT(ename) AS ecount <br>FROM dept,emp <br>WHERE emp.deptno(+)=dept.deptno <br>GROUP BY dept.dname B: SELECT dname,(SELECT COUNT(*) AS ecount FROM emp WHERE emp.deptno=dept.deptno) <br>FROM dept C: SELECT dname,COUNT(ename) AS ecount <br>FROM dept LEFT JOIN emp ON emp.deptno=dept.deptno <br>GROUP BY dept.dname D: SELECT dname,COUNT(*) AS ecount <br>FROM dept LEFT JOIN emp ON emp.deptno=dept.deptno <br>GROUP BY dept.dname