背景及需求:
项目现有两张表:一张用户表,表名:users;一张用户登录信息表,表名:user_login_log表。需求是:查询用户的基本信息及用户最近一条登录信息的列表数据。
数据表结构:
CREATE TABLE `users` (
`id` bigint(20) unsigned NOT NULL AUTO_INCREMENT COMMENT '自增无符号主键',
`username` varchar(50) NOT NULL DEFAULT '' COMMENT '用户名',
`created_at` datetime NOT NULL COMMENT '创建时间',
`updated_at` datetime NOT NULL COMMENT '最近一次更新时间',
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT='用户数据表';CREATE TABLE `user_login_log` (
`id` bigint(20) unsigned NOT NULL AUTO_INCREMENT COMMENT '自增无符号主键',
`user_id` bigint(20) unsigned NOT NULL COMMENT '用户ID',
`login_ip` varchar(50) NOT NULL DEFAULT '' COMMENT '登录IP',
`created_at` datetime NOT NULL COMMENT '创建时间',
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT='用户登录数据表';
user_login_log表数据:连表查询用户基本信息及用户最近一条登录信息:
-- 1条sql语句连表查询用户基本信息及用户最近一条登录信息
select a.id, a.username, a.created_at, a.updated_at, b.login_ip
from users as a left join (
select d.user_id, d.login_ip from (
select max(id) as id from user_login_log group by user_id
) as c left join user_login_log as d on d.id = c.id
) as b on b.user_id = a.id
order by a.id desc;查询结果:
| 留言与评论(共有 0 条评论) “” |