概述
今天主要介绍一下Oracle数据库中多表关联批量插入、多表关联批量更新和多表关联批量删除。下面用实验来理解下~
一、创建必须的表和序列语句
--创建部门表 dept:CREATE TABLE dept( deptno NUMBER(2) CONSTRAINT PK_DEPT PRIMARY KEY, dname VARCHAR2(14) , loc VARCHAR2(13) , CREATEDTIME DATE, UPDATEDTIME DATE, CREATEDBY NUMBER(7,0), UPDATEDBY NUMBER(7,0)) ; --创建员工表 emp:CREATE TABLE emp( empno NUMBER(4) CONSTRAINT PK_EMP PRIMARY KEY, ename VARCHAR2(10), job VARCHAR2(15), mgr NUMBER(4), hiredate DATE, sal NUMBER(7,2), comm NUMBER(7,2), deptno NUMBER(2) CONSTRAINT FK_DEPTNO REFERENCES DEPT, CREATEDTIME DATE, UPDATEDTIME DATE, CREATEDBY NUMBER(7,0), UPDATEDBY NUMBER(7,0)); --创建员工表 emp_copy:CREATE TABLE emp_copy( empno NUMBER(4), ename VARCHAR2(10), job VARCHAR2(15), mgr NUMBER(4), hiredate DATE, sal NUMBER(7,2), comm NUMBER(7,2), deptno NUMBER(2), CREATEDTIME DATE, UPDATEDTIME DATE, CREATEDBY NUMBER(7,0), UPDATEDBY NUMBER(7,0) );--自定义一个序列 create sequence emp_sequence increment by 1 --每次增加几个，我这里是每次增加1 start with 1 --从1开始计数 nomaxvalue --不设置最大值 nocycle --一直累加，不循环 nocache --不建缓冲区 ;--插入dept表数据:INSERT INTO dept VALUES(10,'ACCOUNTING','NEW YORK',sysdate,sysdate,123123,123123);INSERT INTO dept VALUES (20,'RESEARCH','DALLAS',sysdate,sysdate,123123,123123);INSERT INTO dept VALUES(30,'SALES','CHICAGO',SYSDATE,SYSDATE,123123,123123);INSERT INTO dept VALUES(40,'OPERATIONS','BOSTON',sysdate,sysdate,123123,123123); --插入emp表数据:INSERT INTO emp VALUES(7369,'SMITH','CLERK',7902,to_date('17-12-1980','dd-mm-yyyy'),800,NULL,20,sysdate,sysdate,123123,123123);INSERT INTO emp VALUES(7499,'ALLEN','SALESMAN',7698,to_date('20-2-1981','dd-mm-yyyy'),1600,300,30,sysdate,sysdate,123123,123123);INSERT INTO emp VALUES(7521,'WARD','SALESMAN',7698,to_date('22-2-1981','dd-mm-yyyy'),1250,500,30,SYSDATE,SYSDATE,123123,123123);INSERT INTO emp VALUES(7566,'JONES','MANAGER',7839,to_date('2-4-1981','dd-mm-yyyy'),2975,NULL,20,sysdate,sysdate,123123,123123);INSERT INTO emp VALUES(7654,'MARTIN','SALESMAN',7698,to_date('28-9-1981','dd-mm-yyyy'),1250,1400,30,SYSDATE,SYSDATE,123123,123123);INSERT INTO emp VALUES(7698,'BLAKE','MANAGER',7839,to_date('1-5-1981','dd-mm-yyyy'),2850,NULL,30,sysdate,sysdate,123123,123123);INSERT INTO emp VALUES(7782,'CLARK','MANAGER',7839,to_date('9-6-1981','dd-mm-yyyy'),2450,NULL,10,SYSDATE,SYSDATE,123123,123123);INSERT INTO emp VALUES(7788,'SCOTT','ANALYST',7566,to_date('19-4-87','dd-mm-yyyy'),3000,NULL,20,SYSDATE,SYSDATE,123123,123123);INSERT INTO emp VALUES(7839,'KING','PRESIDENT',NULL,to_date('17-11-1981','dd-mm-yyyy'),5000,NULL,10,sysdate,sysdate,123123,123123);INSERT INTO emp VALUES(7844,'TURNER','SALESMAN',7698,to_date('8-9-1981','dd-mm-yyyy'),1500,0,30,SYSDATE,SYSDATE,123123,123123);INSERT INTO emp VALUES(7876,'ADAMS','CLERK',7788,to_date('23-5-87','dd-mm-yyyy'),1100,NULL,20,sysdate,sysdate,123123,123123);INSERT INTO emp VALUES(7900,'JAMES','CLERK',7698,to_date('3-12-1981','dd-mm-yyyy'),950,NULL,30,sysdate,sysdate,123123,123123);INSERT INTO emp VALUES(7902,'FORD','ANALYST',7566,to_date('3-12-1981','dd-mm-yyyy'),3000,NULL,20,SYSDATE,SYSDATE,123123,123123);INSERT INTO emp VALUES(7934,'MILLER','CLERK',7782,to_date('23-1-1982','dd-mm-yyyy'),1300,NULL,10,sysdate,sysdate,123123,123123);
其中e.job = t.job and e.ename = t.ename只是展示可以关联多个条件,这里有一个关键点为 USING ( … ) t 中查询到的是一个list,而merge可以对匹配到的list进行批量更新
四、多表关联批量删除
要求:批量删除部门dept表 loc在 CHICAGO的,且工资小于1500的人员信息
DELETE FROM( SELECT c.* FROM emp c,dept d WHERE d.deptno = c.deptno AND d.loc = 'CHICAGO' and c.sal < 1500);
觉得有用的朋友多帮忙转发哦！后面会分享更多devops和DBA方面的内容，感兴趣的朋友可以关注下~
