SELECT column_name(s) FROM table_name1 INNER JOIN table_name2 ON table_name1.column_name=table_name2.column_name
CREATE TABLE `user` ( `id` int(32) NOT NULL AUTO_INCREMENT, `name` varchar(16) NOT NULL, `kindid` int(32) NOT NULL, PRIMARY KEY (`id`) ) ENGINE=MyISAM DEFAULT CHARSET=utf8;
CREATE TABLE `userkind` ( `id` int(32) NOT NULL AUTO_INCREMENT, `kindname` varchar(16) NOT NULL, PRIMARY KEY (`id`) ) ENGINE=MyISAM DEFAULT CHARSET=utf8;
Enter password: **** Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 2 Server version: 5.5.40 MySQL Community Server (GPL) Copyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. mysql> use join; Database changed mysql> select * from `user`; +----+------+--------+ | id | name | kindid | +----+------+--------+ | 1 | 小明 | 1 | | 2 | 小红 | 1 | | 3 | 涵涵 | 2 | +----+------+--------+ 3 rows in set (0.00 sec) mysql> select * from `userkind`; +----+----------+ | id | kindname | +----+----------+ | 1 | 普通会员 | | 2 | VIP会员 | +----+----------+ 2 rows in set (0.00 sec) mysql> select * from `user` inner join `userkind` on user.kindid=userkind.id; +----+------+--------+----+----------+ | id | name | kindid | id | kindname | +----+------+--------+----+----------+ | 1 | 小明 | 1 | 1 | 普通会员 | | 2 | 小红 | 1 | 1 | 普通会员 | | 3 | 涵涵 | 2 | 2 | VIP会员 | +----+------+--------+----+----------+ 3 rows in set (0.02 sec) mysql> select `id` as `用户ID`,`name` as `用户名`,`kindname` as `用户类别` from `user` inner join `userkind` where user.kindid=userkind.id; ERROR 1052 (23000): Column 'id' in field list is ambiguous mysql> select `user`.`id` as `用户ID`,`name` as `用户名`,`kindname` as `用户类别 ` from -> `user` inner join `userkind` where `user`.`kindid`=`userkind`.`id`; +--------+--------+----------+ | 用户ID | 用户名 | 用户类别 | +--------+--------+----------+ | 1 | 小明 | 普通会员 | | 2 | 小红 | 普通会员 | | 3 | 涵涵 | VIP会员 | +--------+--------+----------+ 3 rows in set (0.00 sec) mysql> select `user`.`id` as `用户ID`,`name` as `用户名`,`kindname` as `用户类别 ` from `user` inner join `userkind` on `user`.`kindid`=`userkind`.`id`; +--------+--------+----------+ | 用户ID | 用户名 | 用户类别 | +--------+--------+----------+ | 1 | 小明 | 普通会员 | | 2 | 小红 | 普通会员 | | 3 | 涵涵 | VIP会员 | +--------+--------+----------+ 3 rows in set (0.00 sec) mysql>
机械节能产品生产企业官网模板...
大气智能家居家具装修装饰类企业通用网站模板...
礼品公司网站模板
宽屏简约大气婚纱摄影影楼模板...
蓝白WAP手机综合医院类整站源码(独立后台)...苏ICP备2024110244号-2 苏公网安备32050702011978号 增值电信业务经营许可证编号:苏B2-20251499 | Copyright 2018 - 2025 源码网商城 (www.ymwmall.com) 版权所有