建议养成 写字段名的好习惯

下面 给你个例子：

  <sql id="SysUserDefineJoins">

a.id AS "id",

a.name AS "name",

a.login_name AS "loginName",

a.login_password AS "loginPassword",

a.create_time AS "createTime",

a.update_time AS "updateTime"

</sql>

<select id="getUser" resultType="com.webpu.m.entity.SysUser">

SELECT 

<include refid="SysUserDefineJoins"/>

FROM sys_user a 

WHERE a.id = #{id}  

</select>

*代表你把这张表里面的所有的列都查出来了.如果换成列名的话，就只查你写的列，这样效率更高