1.配置全局参数，驼峰命名法转换字段（减少mapper的配置）
mybatis-config.xml
<settings><!-- 使用驼峰命名法转换字段。 -->
<setting name="mapUnderscoreToCamelCase" value="true" />
</settings>
2.多表查询字段注入
public class User implements Serializable{private static final long serialVersionUID = 1L;
private String id; //用户编号
private String name; //用户名
private String account; //用户账号
private String password; //用户密码
private String delFlag; //删除标记：1代表存在，0代表删除
private String salt;
private Role role; // 根据角色查询用户条件
......
}
public class Role implements Serializable {
private static final long serialVersionUID = 1L;
private String id;
private String name;
private String enName;
......
}
<select id="get" resultType="User">
select u.*,r.id as `role.id`
FROM user u, role r, user_role ur
where u.id = ur.user_id and ur.role_id = r.id
and u.id = #{id}
</select>