[java论坛] log4j.properties文件配置及说明

最后注意：

得到一个新的maven 项目请做如下操作：

再次：

/mybatis/src/main/java/sy/mapping/UserMapper.xml

<resultMap type="sy.model.User" id="userResultMap3" extends="BaseResultMap">

<collection property="groupUsers" javaType="list" ofType="sy.model.GroupUser">

<id column="groupuser_id" property="id" />

<result column="user_id" property="userid" />

<result column="group_id" property="groupid" />

<association property="groups" javaType="sy.model.Group">

<id property="id" column="groupid"/>

<result property="groupname" column="group_name"/>

</association>

</collection>

</resultMap>

<select id="getAll3" resultMap="userResultMap3">

SELECT

`user`.id,

`user`.`name`,

`user`.loginname,

`user`.pwd,

`user`.mobile,

group_user.id groupuser_id ,

group_user.userid user_id,

group_user.groupid group_id,

`group`.id groupid,

`group`.groupname group_name

FROM

`user`

JOIN group_user ON `user`.id = group_user.userid

JOIN `group` ON group_user.groupid = `group`.id

</select>

简化一下语法为：

SELECT

`user`.id,

`user`.`name`,

`user`.loginname,

`user`.pwd,

`user`.mobile,

group_user.id groupuser_id ,

group_user.userid user_id,

group_user.groupid group_id,

`group`.id groupid,

`group`.groupname group_name,

`group`.createtime group_createtime

FROM

`user`

JOIN group_user ON `user`.id = group_user.userid

JOIN `group` ON group_user.groupid = `group`.id

最后语法为：

SELECT

`user`.id,

`user`.`name`,

`user`.loginname,

`user`.pwd,

`user`.sex,

`user`.mobile,

group_user.id,

group_user.userid,

group_user.groupid,

`group`.id,

`group`.groupname,

`group`.createtime

FROM

`user`

INNER JOIN group_user ON `user`.id = group_user.userid

INNER JOIN `group` ON group_user.groupid = `group`.id

刚只是优化找到了groupid,最后找出user 对应 group name:

回到/mybatis/src/main/java/sy/mapping/UserMapper.xml

返回 /mybatis/src/main/java/sy/model/User.java

这里不要动

package sy.model;

import java.util.List;

public class User {

//1、user里面加入中间表角色分组用户表模块

private List<GroupUser> groupUsers;

//2、Alt+Shift+s自动生成GET SET方法

    public List<GroupUser> getGroupUsers() {

return groupUsers;

}

public void setGroupUsers(List<GroupUser> groupUsers) {

this.groupUsers = groupUsers;

}