本文介绍了sql连接两个表的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
TABLE A >>用户名1 次测试 12 测试23 测试34 测试4表 B >>用户名地址1个地址12 地址24 地址3结果1 test1 address12 test2 地址23 测试34 test4 address3谁能告诉我如何编写查询并获取上述结果，非常感谢！我试过加入，左右加入.结果一无所获.
解决方案
你可以在这两个表之间写左外连接最好的理解方法是查看下图
查询您的需求
SELECT A.uid, A.name, B.address FROM A LEFT JOIN B ON A.uid=B.uid阅读这篇关于代码项目的原创文章会对您有很大帮助:.
TABLE A >>
uid name
1 test1
2 test2
3 test3
4 test4
TABLE B >>
uid address
1 address1
2 address2
4 address3
RESULT
1 test1 address1
2 test2 address2
3 test3
4 test4 address3
Can anyone show me how to write a query and fetch the result as above, Thanks very much! i have tried join, left and right join. all result nothing.
解决方案
You can write left outer join between this two tables Best way to understand is check the below image
Query for your requirement
SELECT A.uid, A.name, B.address FROM A LEFT JOIN B ON A.uid=B.uid
Reading this original article on The Code Project will help you a lot: Visual Representation of SQL Joins.
Find original one at: Difference between JOIN and OUTER JOIN in MySQL.
这篇关于sql连接两个表的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持编程学习网！
本站部分内容来源互联网,如果有图片或者内容侵犯您的权益请联系我们删除！