今天oracle总结

create table emps1 as select * from emps; //备份一个emps表，创建一个和emps一样的表emps1

insert into emps(属性) values(属性值);//在表emps中插入一条新的内容，注意： 在添加不完整信息的时候，所添加的属性必须有约束性的属性

delete from emps where empno=7936;//删除表emps中empno=7936的那一条信息

update emps set ename='malin' where empno=7937;//更新empno=7937的ename，将ename改为malin

集合类型

select * from emp where sal between 800 and 1300

intersect

select * from emp where sal between 1200 and 1400;

EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO

---------- ---------- --------- ---------- -------------- ----- ----- ------

7521 WARD SALESMAN 7698 22-2月 -81 1250 500 30

7654 MARTIN SALESMAN 7698 28-9月 -81 1250 1400 30

7934 MILLER CLERK 7782 23-1月 -82 1300 10

//显示表emp中同时满足两个条件的员工信息，即显示表emp中sal在1200～1300之间的员工信息

select * from emp where sal between 800 and 1300

union

select * from emp where sal between 1200 and 1400

EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO

------- ---------- --------- ---------- -------------- ----- ----- ------

7369 SMITH CLERK 7902 17-12月-80 800 20

7521 WARD SALESMAN 7698 22-2月 -81 1250 500 30

7654 MARTIN SALESMAN 7698 28-9月 -81 1250 1400 30

7876 ADAMS CLERK 7788 12-1月 -83 1100 20

7900 JAMES CLERK 7698 03-12月-81 950 30

7934 MILLER CLERK 7782 23-1月 -82 1300 10

select * from emp where sal between 800 and 1300

union all

select * from emp where sal between 1200 and 1400

EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO

--------- ---------- --------- ---------- -------------- ----- ----- ------

7369 SMITH CLERK 7902 17-12月-80 800 20

7521 WARD SALESMAN 7698 22-2月 -81 1250 500 30

7654 MARTIN SALESMAN 7698 28-9月 -81 1250 1400 30

7876 ADAMS CLERK 7788 12-1月 -83 1100 20

7900 JAMES CLERK 7698 03-12月-81 950 30

7934 MILLER CLERK 7782 23-1月 -82 1300 10

7521 WARD SALESMAN 7698 22-2月 -81 1250 500 30

7654 MARTIN SALESMAN 7698 28-9月 -81 1250 1400 30

7934 MILLER CLERK 7782 23-1月 -82 1300 10

//union 显示的是符合条件但是不包括重复信息 union all 查询符合两个条件的信息，会显示重复信息注意：会有重复信息，因为两个条件中有相同的小条件

select * from emp where sal between 800 and 1300

minus

select * from emp where sal between 1200 and 1400

EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO

------- ---------- --------- ---------- -------------- ----- ----- ------

7369 SMITH CLERK 7902 17-12月-80 800 20

7876 ADAMS CLERK 7788 12-1月 -83 1100 20

7900 JAMES CLERK 7698 03-12月-81 950 30

//显示的是符合前面条件且不符合后面条件的信息

Oracle分页查询

SQL> select rownum,e.* from emp e where rownum<=3;

ROWNUM EMPNO ENAME JOB MGR HIREDATE SAL COMM

DEPTNO

---------- ---------- ---------- --------- ---------- -------------- ----- -----

------

1 7369 SMITH CLERK 7902 17-12月-80 800

20

2 7499 ALLEN SALESMAN 7698 20-2月 -81 1600 300

30

3 7521 WARD SALESMAN 7698 22-2月 -81 1250 500

30

SQL> select * from (select rownum as r,e.* from emp e) el where el.r>3 and el.r<

=6;

R EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO

---------- ---------- ---------- --------- ---------- -------------- ----- ----- ------

4 7566 JONES MANAGER 7839 02-4月 -81 2975 20

5 7654 MARTIN SALESMAN 7698 28-9月 -81 1250 1400 30

6 7698 BLAKE MANAGER 7839 01-5月 -81 2850 30

//这是没有排序的分页，按表中内容直接分页

SQL> select * from (select rownum as r,e.* from (select * from emp order by sal

desc) e) el where el.r>0 and el.r<=3;

R EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO

---------- ---------- ---------- --------- ---------- -------------- ----- ----- ------

1 7839 KING PRESIDENT 17-11月-81 5000 10

2 7902 FORD ANALYST 7566 03-12月-81 3000 20

3 7788 SCOTT ANALYST 7566 09-12月-82 3000 20

SQL> select * from (select rownum as r,e.* from (select * from emp order by sal

desc) e) el where el.r>3 and el.r<=6;

R EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO

---------- ---------- ---------- --------- ---------- -------------- ----- ----- ------

4 7566 JONES MANAGER 7839 02-4月 -81 2975 20

5 7698 BLAKE MANAGER 7839 01-5月 -81 2850 30

6 7782 CLARK MANAGER 7839 09-6月 -81 2450 10

//有排序的分页，以工资的多少为例