简单查询部分sql练习题
-- 选择部门30中的所有职工select * from emp where deptno = 30;-- 列出所有业务员(CLERK)的姓名，编号，和部门编号select e.ename, e.empno, e.deptno from emp e where e.job = 'CLERK';-- 找出奖金高于薪金的员工select * from emp where comm > sal;-- 找出奖金高于薪金的60%的员工select * from emp where comm > sal * 0.6;-- 找出部门10中所有经理(MANAGER)和部门20中所有业务员(CLERK)的详细资料select * from emp e where e.deptno = 10 and e.job = 'MANAGER' or e.deptno = 20 and e.job = 'CLERK';select * from emp e where (e.deptno = 10 and e.job = 'MANAGER') or (e.deptno = 20 and e.job = 'CLERK');select * from emp e where e.deptno = 10 and e.job = 'MANAGER'union select * from emp e where e.deptno = 20 and e.job = 'CLERK';-- 找出部门10中所有经理(MANAGER),部门20中所有业务员(CLERK),既不是经理又不是业务员但其薪水大于等于2000的所有员工的详细资料select * from emp e where e.deptno = 10 and e.job = 'MANAGER' unionselect * from emp e where e.deptno = 20 and e.job = 'CLERK'union select * from emp e where e.sal > 2000 and e.job not in('MANAGER', 'CLERK');-- 找出收取奖金的员工的不同工作select distinct e.job from emp e;-- 找出不收取奖金或收取的奖金低于100的员工select * from emp e where e.comm is null or e.comm < 100;-- 找出各月倒数第3天受雇的所有员工select * from emp e where e.hiredate between last_day(hiredate)-3 and last_day(hiredate);-- 找出早于30年前受雇的员工select * from emp e where (sysdate - e.hiredate)/365 > 30;-- 以首字母大写的方式显示所有员工的姓名select initcap(ename) from emp;-- 显示正好为5个字符的员工姓名select * from emp where length(ename) = 5;-- 显示不带有”R”的员工姓名select * from emp where ename not like '%K%';-- 显示所有员工姓名的前三个字符select substr(ename, 0, 3) from emp;-- 显示所有员工的姓名，并用’a’替换所有’A’select replace(ename, 'A', 'a') from emp;-- 显示满30年服务年限的员工姓名和受雇日期select * from emp where (sysdate - hiredate)/365 > 30;-- 显示员工的详细资料，按姓名由大到小排序select * from emp order by ename desc;-- 显示员工的姓名和受雇日期，根据其服务年限，将最老的员工排在最前面select ename, hiredate from emp order by hiredate asc;-- 显示所有员工的姓名，工作和薪金，按工作降序排列，若工作相同则按薪金升序排序select ename, job, sal from emp order by job desc, sal asc;select ename, job, sal from emp order by 2 desc, 3;-- 显示所有员工的姓名，加入公司的年份和月份，按受雇日期所在的月排序，若月份相同，则将最早年份排在最前面select ename, to_number(to_char(hiredate, 'yyyy')) Year, to_number(to_char(hiredate, 'mm')) from emp order by 3 desc, 2 asc;-- 显示一个月为30天的情况所员工的日薪金，忽略余数select round(sal/30) 日薪 from emp;-- 找出在(任何年份)2月受聘的所有员工select * from emp where to_number(to_char(hiredate, 'mm')）= 2;-- 对每个员工，显示其加入公司的天数select ename, round(sysdate - hiredate) Days from emp;-- 显示姓名中任意位置包含“A”的所有员工姓名select * from emp where upper(ename) like '%A%';-- 以年月日方式显示所有员工的服务年限select ename, hiredate, trunc(months_between(sysdate, hiredate) /12) year ,trunc(mod(months_between(sysdate, hiredate) , 12 ) ) months , trunc(sysdate - add_months(hiredate,months_between(sysdate, hiredate))) dayfrom emp ;