mybatis-plus注解版实现多表联查（sql）

mybatis注解版实现多表联查

需求：

用户有角色，角色有权限，需要一次取用户信息包含角色信息及其对应权限

实体类:

package cn.zytao.taosir.common.model.user;

import java.io.Serializable;
import java.util.Date;
import java.util.HashSet;
import java.util.Set;

import com.baomidou.mybatisplus.annotations.TableField;

import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import lombok.Data;

@Data
@ApiModel(value="用户实体")
public class User implements Serializable{

    /**
     * 
     */
    private static final long serialVersionUID = -2389902440625641568L;

    @ApiModelProperty(name ="id",value = "ID主键")
    private String id;

    @ApiModelProperty(name ="username",value = "用户名")
    private String username;

    @ApiModelProperty(name ="password",value = "密码")
    private String password;

    @ApiModelProperty(name ="nickname",value = "昵称")
    private String nickname;
    
    @ApiModelProperty(name ="isInsiders",value = "是否内部人员")
    private int isInsiders;

    @ApiModelProperty(name ="phone",value = "联系电话")
    private String phone;

    @ApiModelProperty(name ="email",value = "邮箱")
    private String email;

    @ApiModelProperty(name ="qq",value = "QQ")
    private String qq;

    @ApiModelProperty(name ="wechat",value = "微信")
    private String wechat;

    @ApiModelProperty(name ="question",value = "找回密码问题")
    private String question;

    @ApiModelProperty(name ="answer",value = "找回密码答案")
    private String answer;

    @ApiModelProperty(name ="createTime",value = "创建时间")
    private Date createTime;

    @ApiModelProperty(name ="updateTime",value = "更新时间")
    private Date updateTime;
    
    @TableField(exist = false)
    private Set<Role> roles=new HashSet<>();
}

package cn.zytao.taosir.common.model.user;

import java.io.Serializable;
import java.util.HashSet;
import java.util.Set;

import com.baomidou.mybatisplus.annotations.TableField;

import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import lombok.Data;

/**
 * 
 * @author taosir
 *
 */
@Data
@ApiModel(value="角色实体")
public class Role implements Serializable{

    /**
     * 
     */
    private static final long serialVersionUID = 4710406435745633366L;

    @ApiModelProperty(name ="id",value = "ID主键")
    private String id;
    
    @ApiModelProperty(name ="roleCode",value = "角色代码")
    private String roleCode;
    
    @ApiModelProperty(name ="roleName",value = "角色名称")
    private String roleName;
    
    @TableField(exist = false)
    private Set<Permission> permissions=new HashSet<>();
}

package cn.zytao.taosir.common.model.user;


import java.io.Serializable;

import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import lombok.Data;

@Data
@ApiModel(value="权限实体")
public class Permission implements Serializable{

    /**
     * 
     */
    private static final long serialVersionUID = 1545962188193104351L;

    @ApiModelProperty(name ="id",value = "ID主键")
    private String id;
    
    @ApiModelProperty(name ="permissionCode",value = "权限代码")
    private String permissionCode;
    
    @ApiModelProperty(name ="permissionName",value = "权限名称")
    private String permissionName;
    
    @ApiModelProperty(name="path",value="映射路径")
    private String path;
}

package cn.zytao.taosir.common.model.user;

import java.io.Serializable;

import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import lombok.Data;

@Data
@ApiModel(value="用户角色关系表")
public class UserRole implements Serializable{
    /**
     * 
     */
    private static final long serialVersionUID = 6163369825048118489L;
    @ApiModelProperty(name ="id",value = "ID主键")
    private String id;
    @ApiModelProperty(name ="username",value = "用户名")
    private String username;
    @ApiModelProperty(name ="roleCode",value = "角色代码")
    private String roleCode;
}

package cn.zytao.taosir.common.model.user;

import java.io.Serializable;

import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import lombok.Data;

@Data
@ApiModel(value="角色权限关系表")
public class RolePermission implements Serializable{

    /**
     * 
     */
    private static final long serialVersionUID = -7522662317811377590L;
    @ApiModelProperty(name ="id",value = "ID主键")
    private String id;
    @ApiModelProperty(name ="roleCode",value = "角色代码")
    private String roleCode;
    @ApiModelProperty(name ="permissionCode",value = "权限代码")
    private String permissionCode;
}

注解是swagger2的，无需关注。另外有个 @TableField(exist = false) 该注解标识这个字段非数据库字段

持久层处理：

@Select("select * from  role where role_code in(select role_code from user_role where username = #{username})")
    Set<Role> getUserRoles(String username);

@Select("select * from permission where permission_code in (select permission_code from role_permission where role_code = #{roleCode})")
    Set<Permission> getRolePermissions(String roleCode);

第一个sql为获取用户所拥有角色，第二个sql为获取角色所拥有权限

yml的配置上：

mybatis-plus:
  type-aliases-package: cn.zytao.taosir.common.model.user
  configuration:
    map-underscore-to-camel-case: true

映射实体类，开起对下划线转大写的处理

业务处理上：

    public User findByUsername(String username) {
        User user = userMapper.findByUsername(username);
        Set<Role> roles = userMapper.getUserRoles(username);
        for (Role role : roles) {
            role.setPermissions(roleMapper.getRolePermissions(role.getRoleCode()));
        }
        user.setRoles(roles);
        return user;
    }

这样就可以很方便的解决多表的联查~因为本人比较懒，不想写配置版，也不喜欢在注解上用@Results来标示结果集

仍在不断学习中，如有不妥还望指教~