如下表结构：

CREATE TABLE `t_user` (  `id` int(11) NOT NULL,  `user_name` varchar(50) DEFAULT NULL,  `phone` varchar(11) DEFAULT NULL,  `status` int(11) DEFAULT NULL,  `create_time` timestamp NULL DEFAULT NULL,  `update_time` timestamp NULL DEFAULT NULL,  PRIMARY KEY (`id`)) ENGINE=InnoDB DEFAULT CHARSET=latin1;

    首先 ，查询sql如下: 

     select user_name,phone,status,create_time,update_time

from t_user, 

    

select user_name,phone,status,create_time,update_time

from t_user

union

select user_name,phone,status,create_time,update_time

from t_user; 

去重的sql如下

select user_name,phone,status,create_time,update_time

from t_user

union

select user_name,phone,status,create_time,update_time

from t_user;

结果