解决字段名与实体类属性名不相同的冲突

主要是解决实体类中属性名和数据库中数据表的字段名不同问题,解决办法有2种:

1.查询数据时用别名,

<select id="selectOrder" parameterType="int" resultType="_Order">
    select user_id id, user_name name from orders where user_id=#{id}
</select>

<select id="selectOrder" parameterType="int" resultType="_Order">
	select user_id id, user_name name from orders where user_id=#{id}
</select>

2.或者使用resultMap

<select id="getUser" parameterType="int" resultMap="differMap">
        select * from user_differ where user_id=#{id}
    </select>

    <resultMap id="differMap" type="com.vo.User">
        <id column="user_id" property="id"/>
        <result column="user_name" property="name"/>
    </resultMap>
</mapper>

<select id="getUser" parameterType="int" resultMap="differMap">
        select * from user_differ where user_id=#{id}
    </select>
&lt;resultMap id="differMap" type="com.vo.User"&gt;
    &lt;id column="user_id" property="id"/&gt;
    &lt;result column="user_name" property="name"/&gt;
&lt;/resultMap&gt;

</mapper>

Tip：这两种方法只能使用其中一种否则会报错