在 Django 中，User、Group 和 Permission 是权限系统的核心组件。下面通过代码示例演示它们的 CRUD（创建、读取、更新、删除） 操作：

一、User 模型 CRUD

from django.contrib.auth.models import User# 创建用户
user = User.objects.create_user(username='alice',email='alice@example.com',password='securepassword'
)# 读取用户
user = User.objects.get(username='alice')  # 获取单个用户
users = User.objects.all()                # 获取所有用户
active_users = User.objects.filter(is_active=True)  # 过滤查询# 更新用户
user.email = 'new_email@example.com'
user.is_staff = True
user.save()# 删除用户
user.delete()

二、Group 模型 CRUD

from django.contrib.auth.models import Group, Permission# 创建组
group = Group.objects.create(name='编辑组')# 读取组
group = Group.objects.get(name='编辑组')
groups = Group.objects.all()# 更新组
group.name = '高级编辑组'
group.save()# 删除组
group.delete()# 为组分配权限
permission = Permission.objects.get(codename='add_post')
group.permissions.add(permission)  # 添加单个权限
group.permissions.remove(permission)  # 移除单个权限
group.permissions.clear()  # 清空所有权限

三、Permission 模型 CRUD

from django.contrib.auth.models import Permission
from django.contrib.contenttypes.models import ContentType
from myapp.models import Article  # 假设 Article 是你的模型# 创建自定义权限（通常通过模型的 Meta 类定义）
content_type = ContentType.objects.get_for_model(Article)
permission = Permission.objects.create(codename='can_publish',name='Can publish articles',content_type=content_type
)# 读取权限
permission = Permission.objects.get(codename='can_publish')
permissions = Permission.objects.filter(content_type=content_type)# 更新权限
permission.name = 'Can publish and unpublish articles'
permission.save()# 删除权限
permission.delete()

四、关联操作

1. 用户与组的关联

user = User.objects.get(username='alice')
group = Group.objects.get(name='编辑组')user.groups.add(group)  # 用户加入组
user.groups.remove(group)  # 用户退出组
user.groups.clear()  # 用户退出所有组
user.groups.set([group])  # 用户只属于指定组

2. 用户与权限的直接关联

permission = Permission.objects.get(codename='add_post')
user.user_permissions.add(permission)  # 直接为用户分配权限
user.user_permissions.remove(permission)  # 移除用户权限
user.user_permissions.clear()  # 清空用户所有权限

五、查询示例

1. 获取用户的所有权限

user = User.objects.get(username='alice')
all_permissions = user.get_all_permissions()  # 返回权限字符串集合

2. 检查用户是否有某个权限

if user.has_perm('myapp.add_article'):print("用户有权限")
else:print("用户无权限")

3. 获取组的所有成员

group = Group.objects.get(name='编辑组')
users_in_group = group.user_set.all()

六、特殊操作

1. 创建超级用户

# 方法 1：命令行创建
python manage.py createsuperuser# 方法 2：代码创建
User.objects.create_superuser(username='admin',email='admin@example.com',password='adminpassword'
)

2. 修改用户密码

user = User.objects.get(username='alice')
user.set_password('new_secure_password')
user.save()

七  模型关系图 

 

# 权限与角色(组)相关联，用户通过称为适当角色(组)的成员而得到这些角色(组)的权限

# 极大的简化了权限的管理(相互依赖)

# Django的Auth组件(app)采用的认证规则就是RBAC

    1 User表                     :存用户信息
    2 Permission表             :存权限
    3 Role表                     :存角色(组)

    4 Group_Role中间表            :权限赋予角色(多对多)
    5 User_Group中间表            :角色赋予用户(多对多)
    6 User_Permission中间表    :权限临时赋予角色(多对多)
        
'''
ps:
    1 Django后台管理admin自带RBAC
'''
 

八 手动实现一下关联关系

from django import models
from datetime import datetime, timezoneclass Permission(models.Model):"""权限表"""name = models.CharField(max_length=255)codename = models.CharField(max_length=100)class Group(models.Model):"""分组表"""name = models.CharField(max_length=150)permissions = models.ManyToManyField(Permission,through='GroupPermission',  # 指定模型through_fields=('group', 'permission'),  # 指定字段blank=True)class User(models.Model):"""用户表"""username = models.CharField(max_length=150)password = models.CharField(max_length=128)email = models.EmailField(max_length=254)fist_name = models.CharField(max_length=30, blank=True)last_name = models.CharField(max_length=150, blank=True)is_active = models.BooleanField(default=True)is_staff = models.BooleanField(default=False)is_superuser = models.BooleanField(default=False)last_login = models.DateTimeField(null=True, blank=True)date_joined = models.DateTimeField(null=True, default=timezone.now)groups = models.ManyToManyField(Group,through='UserGroup',  # 指定模型through_fields=('user', 'group'),  # 指定字段blank=True)user_permissions = models.ManyToManyField(Permission,through='UserPermission',  # 指定模型through_fields=('user', 'permission'),  # 指定字段blank=True)class UserGroup(models.Model):"""用户和分组关系表"""user_id = models.ForeignKey(User, on_delete=models.CASCADE)group_id = models.ForeignKey(Group, on_delete=models.CASCADE)class UserPermission(models.Model):"""用户和权限关系表"""user_id = models.ForeignKey(User, on_delete=models.CASCADE)permission_id = models.ForeignKey(Permission, on_delete=models.CASCADE)

九 自动关联关系

class Permission(models.Model):"""权限表"""name = models.CharField(max_length=255)codename = models.CharField(max_length=100)class Group(models.Model):"""分组表"""name = models.CharField(max_length=150)permissions = models.ManyToManyField(Permission, blank=True)class User(models.Model):"""用户表"""username = models.CharField(max_length=150)password = models.CharField(max_length=128)email = models.EmailField(max_length=254)fist_name = models.CharField(max_length=30, blank=True)last_name = models.CharField(max_length=150, blank=True)is_active = models.BooleanField(default=True)is_staff = models.BooleanField(default=False)is_superuser = models.BooleanField(default=False)last_login = models.DateTimeField(null=True, blank=True)date_joined = models.DateTimeField(null=True, default=timezone.now)groups = models.ManyToManyField(Group, blank=True)user_permissions = models.ManyToManyField(Permission, blank=True)