若依框架查重

xml：

<select id="checkUserNameUnique" parameterType="String" resultMap="SysCustomerResult">
		select * from sys_customer where user_name = #{userName} limit 1
	</select>

service：

public String checkUserNameUnique(SysCustomer user)
    {
        Long userId = StringUtils.isNull(user.getUserId()) ? -1L : user.getUserId();
        SysCustomer info = userMapper.checkUserNameUnique(user.getUserName());
        if (StringUtils.isNotNull(info) && info.getUserId().longValue() != userId.longValue())
        {
            return UserConstants.NOT_UNIQUE;
        }
        return UserConstants.UNIQUE;
    }

接口：

public SysCustomer checkUserNameUnique(String userName);

controller：

if (UserConstants.NOT_UNIQUE.equals(userService.checkUserNameUnique(user)))
        {
            return AjaxResult.error("修改用户'" + user.getUserName() + "'失败，登录账号已存在");
        }