我们在开发过程中经常面对多对多的情况，那么我们应该怎么做呢？在实际工作中，权限和角色符合一对多的情况，下面我就一简单的RBAC做个简单示例。 权限表
- 一个权限对应多个角色
- 一个角色拥有多个权限
- 通过一个中间表进行关联
package models
type Permission struct {
Model
Path string `json:"path"`
Title string `json:"title"`
ApiPath string `json:"apiPath"`
ParentId uint `json:"parentId" gorm:"default:0"`
Icon string `json:"icon"`
}
角色表
package models
type Role struct {
Model
RoleName string `json:"roleName"`
Description string `json:"description"`
//不同步更新permission表
//Permission []Permission `json:"permission" gorm:"many2many:role_permissions;association_autoupdate:false;association_autocreate:false"`
//同步更新permission表
Permission []Permission `json:"permission" gorm:"many2many:role_permissions"`
}
权限角色关联表
package models
type RolePermission struct {
Model
RoleId uint `json:"roleId"`
PermissionId uint `json:"permissionId"`
}
示例
package main
import (
"ginLearn.com/models"
)
func main() {
db := models.DB()
role := models.Role{}
role.ID = 8
var permissionSlice []models.Permission
//根据角色查询所有权限
//SELECT `permissions`.* FROM `permissions` INNER JOIN `role_permissions`
//ON `role_permissions`.`permission_id` = `permissions`.`id`
//WHERE `permissions`.`deleted_at` IS NULL AND ((`role_permissions`.`role_id` IN (8)))
db.Model(&role).Related(&permissionSlice, "permission")
//我们更新角色的所有权限该怎么做呢？
//1、删除角色的所有的权限
db.Where("role_id=?", role.ID).Unscoped().Delete(&models.RolePermission{})
//2、给角色赋予权限
role.Permission = []models.Permission{permissionSlice[0]}
//更新角色的权限
//UPDATE `roles` SET `updated_at` = '2020-03-24 01:14:17', `deleted_at` = NULL, `role_name` = '', `description` = '' WHERE `roles`.`deleted_at` IS NULL AND `roles`.`id` = 8
//UPDATE `permissions` SET `updated_at` = '2020-03-24 01:14:17', `deleted_at` = NULL, `path` = '', `title` = '仪表盘', `api_path` = '', `parent_id` = 0, `icon` = 'el-icon-monitor
//' WHERE `permissions`.`deleted_at` IS NULL AND `permissions`.`id` = 1
//INSERT INTO `role_permissions` (`role_id`,`permission_id`) SELECT 8,1 FROM DUAL WHERE NOT EXISTS (SELECT * FROM `role_permissions` WHERE `role_id` = 8 AND `permission_id` = 1)
db.Save(&role)
}
在这里，我们演示了多对多关系下的查询和修改，通过角色找到权限；更新角色权限。例外附上了测试的SQL和数据库。需要的小伙伴自行下载。