java face questions MyBatis entity classes in the attribute table and field names in different solutions

1 write sql statement ever since aliases

select id, u_name uname, u_age age from emp; u_name will be mapped to the database entity class attributes uname

2  open hump naming MyBatis in the global configuration file   can be mapped database underlined camelCase underscore Note that the database must be next to the

  <settings>

          <setting name="mapUnderscoreToCamelCase"  value="true"/>   

</settings>

3  in resultMap Mapper mapping file to customize the advanced mapping

 <select id="select01" resultMap="MyMap">

  select * from emp where id=#{id}

</select >

<resultMap  type="com.atguigu.com.entities.emp"  id="MyMap"> 

   <! - mapping the primary key ->

    <id column="id"  property="id"/>

    <! - other columns mapped to the corresponding attribute in the property named entity class ->

<result  column="e_name"  property="ename"/>

</resultMap>