源码-PL/SQL从入门到精通-第六章-查询数据表-Part 1

--第六章开始
--查询特定的列数据
SELECT view_name, text
FROM user_views;

--查询所有列数据
select * from emp;

--使用distinct查询唯一列数据
select distinct job from emp;

--造数据_部门表dept6
create table dept6 as select * from dept where 1=2;

select * from dept6;

INSERT INTO DEPT6
(DEPTNO, DNAME, LOC)
VALUES
(10, '财务部', '纽约');
INSERT INTO DEPT6
(DEPTNO, DNAME, LOC)
VALUES
(20, '研究部', '达拉斯');
INSERT INTO DEPT6
(DEPTNO, DNAME, LOC)
VALUES
(30, '销售部', '芝加哥');
INSERT INTO DEPT6
(DEPTNO, DNAME, LOC)
VALUES
(40, '营运部', '波士顿');
INSERT INTO DEPT6
(DEPTNO, DNAME, LOC)
VALUES
(60, '行政部', '远洋');
INSERT INTO DEPT6
(DEPTNO, DNAME, LOC)
VALUES
(50, '行政部', '波士顿');

--造数据_员工表emp6
create table emp6 as select * from emp where 1=2;
drop table emp6;
alter table emp6 modify job varchar(20);

select * from emp6;

Insert into EMP6
(EMPNO, ENAME, JOB, MGR, HIREDATE,
SAL, COMM, DEPTNO)
Values
(7369, '史密斯', '职员', 7902, TO_DATE('12/17/1980 00:00:00', 'MM/DD/YYYY HH24:MI:SS'),
1755.2, 129.6, 20);
Insert into EMP6
(EMPNO, ENAME, JOB, MGR, HIREDATE,
SAL, COMM, DEPTNO)
Values
(7499, '艾伦', '销售人员', 7698, TO_DATE('02/20/1981 00:00:00', 'MM/DD/YYYY HH24:MI:SS'),
1700, 400, 30);
Insert into EMP6
(EMPNO, ENAME, JOB, MGR, HIREDATE,
SAL, COMM, DEPTNO)
Values
(7521, '沃德', '销售人员', 7698, TO_DATE('02/22/1981 00:00:00', 'MM/DD/YYYY HH24:MI:SS'),
1350, 400, 30);
Insert into EMP6
(EMPNO, ENAME, JOB, MGR, HIREDATE,
SAL, COMM, DEPTNO)
Values
(7566, '约翰', '经理', 7839, TO_DATE('04/02/1981 00:00:00', 'MM/DD/YYYY HH24:MI:SS'),
3570, 297.5, 20);
Insert into EMP6
(EMPNO, ENAME, JOB, MGR, HIREDATE,
SAL, COMM, DEPTNO)
Values
(7654, '马丁', '销售人员', 7698, TO_DATE('02/28/1981 00:00:00', 'MM/DD/YYYY HH24:MI:SS'),
1350, 400, 30);
Insert into EMP6
(EMPNO, ENAME, JOB, MGR, HIREDATE,
SAL, COMM, DEPTNO)
Values
(7698, '布莱克', '经理', 7839, TO_DATE('03/01/1981 00:00:00', 'MM/DD/YYYY HH24:MI:SS'),
2850, 400, 30);
Insert into EMP6
(EMPNO, ENAME, JOB, MGR, HIREDATE,
SAL, COMM, DEPTNO)
Values
(7782, '克拉克', '经理', 7839, TO_DATE('05/09/1981 00:00:00', 'MM/DD/YYYY HH24:MI:SS'),
3587.05, 200, 10);
Insert into EMP6
(EMPNO, ENAME, JOB, MGR, HIREDATE,
SAL, COMM, DEPTNO)
Values
(7788, '斯科特', '职员', 7566, TO_DATE('12/09/1982 00:00:00', 'MM/DD/YYYY HH24:MI:SS'),
1760.2, 129.6, 20);
Insert into EMP6
(EMPNO, ENAME, JOB, MGR, HIREDATE,
SAL, COMM, DEPTNO)
Values
(7839, '金', '老板', NULL, TO_DATE('11/17/1981 00:00:00', 'MM/DD/YYYY HH24:MI:SS'),
8530.5, NULL, 10);
Insert into EMP6
(EMPNO, ENAME, JOB, MGR, HIREDATE,
SAL, COMM, DEPTNO)
Values
(7844, '特纳', '销售人员', 7698, TO_DATE('08/08/1981 00:00:00', 'MM/DD/YYYY HH24:MI:SS'),
1600, 400, 30);
Insert into EMP6
(EMPNO, ENAME, JOB, MGR, HIREDATE,
SAL, COMM, DEPTNO)
Values
(7876, '亚当斯', '职员', 7788, TO_DATE('01/12/1983 00:00:00', 'MM/DD/YYYY HH24:MI:SS'),
1440, 120, 20);
Insert into EMP6
(EMPNO, ENAME, JOB, MGR, HIREDATE,
SAL, COMM, DEPTNO)
Values
(7900, '吉姆', '职员', 7698, TO_DATE('12/03/1981 00:00:00', 'MM/DD/YYYY HH24:MI:SS'),
1050, 400, 30);
Insert into EMP6
(EMPNO, ENAME, JOB, MGR, HIREDATE,
SAL, COMM, DEPTNO)
Values
(7902, '福特', '分析人员', 7566, TO_DATE('12/03/1981 00:00:00', 'MM/DD/YYYY HH24:MI:SS'),
3600, 300, 20);
Insert into EMP6
(EMPNO, ENAME, JOB, MGR, HIREDATE,
SAL, COMM, DEPTNO)
Values
(7892, '张八', NULL, NULL, NULL,
NULL, NULL, 20);
Insert into EMP6
(EMPNO, ENAME, JOB, MGR, HIREDATE,
SAL, COMM, DEPTNO)
Values
(7893, '霍九', NULL, NULL, NULL,
NULL, NULL, 20);
Insert into EMP6
(EMPNO, ENAME, JOB, MGR, HIREDATE,
SAL, COMM, DEPTNO)
Values
(7894, '霍十', NULL, NULL, NULL,
NULL, NULL, 20);
Insert into EMP6
(EMPNO, ENAME, JOB, MGR, HIREDATE,
SAL, COMM, DEPTNO)
Values
(7895, 'APPS', NULL, NULL, TO_DATE('09/05/2011 00:00:00', 'MM/DD/YYYY HH24:MI:SS'),
3000, 200, 20);
Insert into EMP6
(EMPNO, ENAME, JOB, MGR, HIREDATE,
SAL, COMM, DEPTNO)
Values
(7903, '通利', '职员', NULL, TO_DATE('12/04/1981 00:00:00', 'MM/DD/YYYY HH24:MI:SS'),
2000, 200, NULL);
Insert into EMP6
(EMPNO, ENAME, JOB, MGR, HIREDATE,
SAL, COMM, DEPTNO)
Values
(7904, '罗威', '职员', NULL, TO_DATE('12/08/1981 00:00:00', 'MM/DD/YYYY HH24:MI:SS'),
2000, 200, NULL);
Insert into EMP6
(EMPNO, ENAME, JOB, MGR, HIREDATE,
SAL, COMM, DEPTNO)
Values
(7898, 'O''Malley', NULL, NULL, NULL,
NULL, NULL, 20);

SELECT ename, empno, job, hiredate
FROM scott.emp6;

--在查询中使用表达式
SELECT empno, ename, sal * (1 + 0.12)
FROM emp6;

--使用列别名
SELECT empno, ename, sal * (1 + 0.12) raised_sal
FROM emp;
SELECT empno 员工名称, ename "员工姓名_NAME", job 职级, sal AS 薪水
FROM emp;

--字符串连接
SELECT ename || '的薪资为：' || sal 员工薪水
FROM emp;