A: SELECT MAX(empno) FROM scott.emp;
B: SELECT
COUNT(empno) FROM scott.emp;
C: SELECT COUNT(comm) FROM scott.emp;
D: SELECT COUNT(*) FROM scott.emp;
举一反三
- 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;
- 查询scott用户的emp表中的总记录数，可以使用下列哪个语句？
- 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;
- 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
- 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
内容
- 0
【多选题】下列说法正确的是 A. v emp%rowtype; select * into v from emp where empno=7788; 上面代码是正确的。 B. v emp%type; select * into v from emp where empno=7788; 上面代码是正确的。 C. v emp.empno%type; select * int
- 1
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
- 2
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
- 3
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;
- 4
列出所有员工的姓名、部门名称和工资。正确的SQL语句有________。 A: SELECT a.ename <br> ,(SELECT b.dname FROM dept b) AS dname <br> ,sal <br>FROM emp a B: SELECT a.ename <br> ,(SELECT b.dname FROM dept b WHERE b.deptno=a.deptno) AS dname <br> ,sal <br>FROM emp a; C: SELECT a.ename,b.dname,sal <br>FROM emp a,dept D: SELECT a.ename,b.dname,sal <br>FROM emp a,dept b <br>WHERE a.deptno=b.deptno