Join的7中情况
2024-09-05 22:40:33
一、左外连接
SELECT * FROM A LEFT JOIN B ON A.KEY = B.KEY
二、右外连接
SELECT * FROM A RIGHT JOIN B ON A.KEY = B.KEY
三、内连接
SELECT * FROM A INNER JOIN B ON A.KEY = B.KEY
四、全连接
1 SELECT * FROM A FULL OUTER JOIN B ON A.KEY = B.KEY #Mysql不支持
SELECT * FROM A LEFT JOIN B ON A.KEY=B.KEY
UNION
SELECT * FROM A RIGHT JOIN B ON A.KEY=B.KEY
五、左连接
SELECT * FROM A LEFT JOIN B ON A.KEY = B.KEY WHERE B.KEY IS NULL
六、右连接
SELECT * FROM A RIGHT JOIN B ON A.KEY = B.KEY WHERE A.KEY IS NULL
七、全外连接
1 SELECT * FROM A FULL OUTER JOIN B ON A.KEY = B.KEY WHERE A.KEY IS NULL OR B.KEY IS NULL #mysql不支持
SELECT * FROM A LEFT JOIN B ON A.KEY=B.KEY WHERE B.KEY IS NULL
UNION
SELECT * FROM A RIGHT JOIN B ON A.KEY=B.KEY WHERE A.KEY IS NULL
最新文章
- 【实战Java高并发程序设计6】挑战无锁算法:无锁的Vector实现
- 首次创建maven项目的准备工作
- 2016.9.13 JavaScript入门之六基础函数
- VS下如何调试多线程
- Java程序员必备的6款最佳开发工具
- ControlsFX8.0.2中对话框无法判断是否显示的修改
- 探讨VMP 2.12.3 导入表修复
- 我的MYSQL学习心得 mysql日志
- Single Image Haze Removal Using Dark Channel Prior
- code force 403B.B. The Meeting Place Cannot Be Changed
- 动态WebApi
- 关于jmeter工具使用的总结
- 【java】-- 线程安全
- Posche Piwis 3 Original and Clone – What’s the difference
- elementui分页点击详情返回分页样式
- poj3069 Saruman's Army(贪心)
- eclipse get set 自动添加注释
- Java获取数据库表 字段 存储的部分数据
- Java中的关键字
- SQL语句的三大类