Mybatis return Map

In Mybatis, we often use such as the following:

Returns a result

User selectOne(User user);

<select id="selectOne"  parameterType="cn.lyn4ever.entity.User"  resultType="cn.lyn4ever.entity.User">
       select id,username,telphone from user where telphone=#{telphone} and password = #{password}
    </select>

Return multiple results (and in fact the top, in that it is the only control query)

List<User> selectList(User user);

<select id="selectOne"  parameterType="cn.lyn4ever.entity.User"  resultType="cn.lyn4ever.entity.User">
       select id,username,telphone from user
    </select>

We just on top of the `resultType`change `java.util.HashMap`, so it will generate the following

Map selectList(User user);

<select id="selectOne"  parameterType="cn.lyn4ever.entity.User"  parameterType="cn.lyn4ever.entity.User"   resultType="java.util.HashMap">
       select id,username,telphone from user where telphone=#{telphone} and password = #{password}
    </select>

This result is to say, the User class attribute-called key, attribute value value.

Of course, you can also check out the many records, this Map into a List

List<Map> selectList(User user);

<select id="selectOne"  parameterType="cn.lyn4ever.entity.User"  resultType="java.util.HashMap">
       select id,username,telphone from user
    </select>

But sometimes we want this result, how to do it?

{
    "01":{
        username:"zhangsan",
        telphone:"13000000000"
    }
}

This is what we want to customize a Map <String, User>, this is the case, there are two solutions:

1. Notes

@MapKey("id")
Map<String,User> getUserInMap();

<!--xml和之前写法一样-->
<select id="getUserInMap" parameterType="cn.lyn4ever.entity.User"   resultType="User">
   select id,username,telphone from user where telphone=#{telphone} and password = #{password}
</select>

The value of a property @MapKey is written User objects

2. Write on the xml file

　HashMap<String,Object> getUserInMap();

<select id="getUserInMap" parameterType="cn.lyn4ever.entity.User"   resultType="java.util.HashMap">
SELECT id as 'key', * as 'value', id,username,telphone from user where telphone=#{telphone} and password = #{password}
</select>

Of course, the above two methods, if you check out a number of words will be List的形式