在多个mapper.xml中重用MyBatis ResultMap [英] Reusing MyBatis ResultMap in multiple mapper.xml

问题描述

我想重用来自不同* Mapper.xml文件的特定文件，这些文件都以某种方式读取相同的对象.

我有一个名为Project的数据库表，我为此创建了以下resultMap:

<resultMap id="ProjectMap" type="com.model.Project">
    <id column="id" jdbcType="BIGINT" property="id" />
    <result column="name" jdbcType="VARCHAR" property="name" />
    <result column="client_prj_no" jdbcType="VARCHAR" property="clientPrjNo" />
    <result column="notes" jdbcType="VARCHAR" property="notes" />
    <result column="start_date" jdbcType="TIMESTAMP" property="startDate" />
    ...
<resultMap>

它在ProjectMapper.xml中很好用，但是，现在我想创建一个ClientWithProjectsMapper.xml，在其中我要从* CLIENT中选择* PROJECT，其中PROJECT.CLIENT_ID = CLIENT.ID，并让一个Client对象返回一个列表对象.换句话说，我想使用一个SQL获得ClientWithProjects.

在映射中，我想重用我在ProjectMapper.xml中定义的ProjectMap(没有复制/粘贴)，但是我不确定如何做到这一点.

我可以将ProjectMap分解为一个单独的文件，但是我没有在MyBatis中找到任何设施来#include其他文件.

关于如何做到这一点的任何想法? (我正在使用Maven，是否有任何插件可以过滤查找#include等文件，并将文件内容直接包含在正在处理的文件中?)

谢谢.

-AP_

解决方案

在mybatis-config.xml文件中导入所有映射器xml之后，您可以使用resultMap id和名称空间引用在任何映射器xml中配置的ResultMap. /p>

例如: ProjectMapper.xml

<mapper namespace="com.mybatisapp.mappers.ProjectMapper">
    <resultMap id="ProjectMap" type="com.model.Project">
        <id column="id" jdbcType="BIGINT" property="id" />
        <result column="name" jdbcType="VARCHAR" property="name" />     
    <resultMap>
</mapper>

在ClientWithProjectsMapper.xml中

    <select id="selectProjectsByClient" parameterType="int" 
resultMap="com.mybatisapp.mappers.ProjectMapper.ProjectMap">
    select * from blahblah
    </select>

此处您可以使用完全限定的名称作为"com.mybatisapp.mappers.ProjectMapper.ProjectMap"

在另一个Mapper xml文件中引用resultMap.

I would like to re-use a specific from different *Mapper.xml files which all somehow read same objects.

I have a Database table called Project, which I created the following resultMap for:

<resultMap id="ProjectMap" type="com.model.Project">
    <id column="id" jdbcType="BIGINT" property="id" />
    <result column="name" jdbcType="VARCHAR" property="name" />
    <result column="client_prj_no" jdbcType="VARCHAR" property="clientPrjNo" />
    <result column="notes" jdbcType="VARCHAR" property="notes" />
    <result column="start_date" jdbcType="TIMESTAMP" property="startDate" />
    ...
<resultMap>

It works great in the ProjectMapper.xml, however, now I want to create a ClientWithProjectsMapper.xml where I want to SELECT * FROM CLIENT, PROJECT where PROJECT.CLIENT_ID = CLIENT.ID and have a Client object return with a List objects. In other words, I want to get a ClientWithProjects with a single SQL.

In my mapping, I want to reuse the ProjectMap (without copy/paste) which I defined in the ProjectMapper.xml, but I am not sure how to accomplish this.

I could factor out the ProjectMap into a separate file, but I have not found any facilities in MyBatis to #include other files.

Any ideas on how this can be done? (I am using Maven, are there any plugins that would filter the files looking for #include or such, and include the contents of the file right into file being processed?).

Thanks.

-AP_

解决方案

Once you import all the mapper xmls in mybatis-config.xml file you can refer ResultMaps configured in any of the mapper xmls using resultMap id along with namespace.

for Ex: ProjectMapper.xml

<mapper namespace="com.mybatisapp.mappers.ProjectMapper">
    <resultMap id="ProjectMap" type="com.model.Project">
        <id column="id" jdbcType="BIGINT" property="id" />
        <result column="name" jdbcType="VARCHAR" property="name" />     
    <resultMap>
</mapper>

In ClientWithProjectsMapper.xml

    <select id="selectProjectsByClient" parameterType="int" 
resultMap="com.mybatisapp.mappers.ProjectMapper.ProjectMap">
    select * from blahblah
    </select>

Here you can reference resultMap in another Mapper xml files using fully qualified name as "com.mybatisapp.mappers.ProjectMapper.ProjectMap"

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