MYBATIS多层嵌套查询
基于权限管理时的用户角色权限处理。
实体类:
1.User
public class User{
private Integer uid;
private String username;
private String password;
private Set<Role> roles=new HashSet<>();
2.Role
public class Role {
private Integer rid;
private String rname;
private Set<Module> modules=new HashSet<>();
3.Module
Mapper 文件。
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|
<
resultMap
id="userMap2" type="com.example.mapper.entity.User">
<
id
property="uid" column="uid"/>
<
result
property="username" column="username"/>
<
result
property="password" column="password"/>
<
collection
property="roles" ofType="roleMap" column="uid" select="findRole"></
collection
>
</
resultMap
>
<
resultMap
id="roleMap" type="com.example.mapper.entity.Role">
<
id
property="rid" column="rid"/>
<
result
property="rname" column="rname"/>
<
collection
property="modules" ofType="com.example.mapper.entity.Module" column="rid" select="findModule">
</
collection
>
</
resultMap
>
<
select
id="findUserByUserName" parameterType="java.lang.String" resultMap="userMap2">
SELECT * from USER WHERE username=#{username}
</
select
>
<
select
id="findRole" parameterType="java.lang.Integer" resultMap="roleMap">
SELECT r.* from Role r LEFT JOIN user_role ur on ur.rid =r.rid where ur.uid=#{uid}
</
select
>
<
select
id="findModule" parameterType="java.lang.Integer" resultType="com.example.mapper.entity.Module">
SELECT m.* from module m LEFT JOIN module_role mr on mr.mid =m.mid where mr.rid=#{rid}
</
select
>
|
测试结果。
User{uid=1, username='hlhdidi', password='123', roles=[Role{rid=1, rname='admin',modules=[Module{mid=2, mname='delete'}, Module{mid=3, mname='query'}, Module{mid=4, mname='update'}, Module{mid=1, mname='add'}]}]}