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mysql——多表——合并查询结果

时间:2019-12-24 20:51:57      阅读:102      评论:0      收藏:0      [点我收藏+]

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合并查询结果

合并查询结果 是将多个select语句的查询结果合并到一起

union关键字,数据库会将所有的查询结果合并到一起,然后除掉相同的记录;

union all关键字,只是简单的合并到一起

 

前期表准备:

create table employee ( num int(50),
                        d_id int(50),
                        name varchar(50),
                        age int(50),
                        sex varchar(50),
                        homeadd varchar(50)
                       );

insert into employee values(1,1001,zhangsan,26,nan,beijing);
insert into employee values(2,1001,lisi,24,nv,hunan);
insert into employee values(3,1002,wangwu,25,nan,jiangsu);
insert into employee values(4,1004,aric,15,nan,yingguo);

select * from employee;

create table department ( d_id int(50),
                          d_name varchar(50),
                          functione varchar(50),
                          address varchar(50)
                        );

insert into department values(1001,keyanbu,yanfachanpin,3lou5hao);
insert into department values(1002,shengchanbu,shengchanchanp,5louyiceng);
insert into department values(1003,xiaoshoubu,cehuaxiaoshou,1louxiaoshoudating);

select * from department;

 

select d_id from department union select d_id from employee;

技术图片

 

 

 

 

 

 

select d_id from department union all select d_id from employee;

技术图片

mysql——多表——合并查询结果

标签:val   arch   alt   wan   cti   ima   UNC   address   res   

原文地址:https://www.cnblogs.com/xiaobaibailongma/p/12093142.html

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