MYBATIS多层嵌套查询
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'}]}]}