修改group的models添加小组管理员的多对多字段，把原来的管理员字段重命名为创建者

group/models.py

@@ -8,10 +8,11 @@ class Group(models.Model):
     name = models.CharField(max_length=30, unique=True)
     description = models.TextField()
     create_time = models.DateTimeField(auto_now_add=True)
-    admin = models.ForeignKey(User, related_name="my_groups")
+    created_by = models.ForeignKey(User, related_name="my_groups")
     # 0是公开 1是需要申请后加入 2是不允许任何人加入
     join_group_setting = models.IntegerField(default=1)
     members = models.ManyToManyField(User, through="UserGroupRelation")
+    admin = models.ManyToManyField(User, through="AdminGroupRelation", related_name="managed_groups")
     # 解散小组后，这一项改为False
     visible = models.BooleanField(default=True)
 
@@ -29,6 +30,16 @@ class UserGroupRelation(models.Model):
         unique_together = ("group", "user")
         
 
+
+class AdminGroupRelation(models.Model):
+    user = models.ForeignKey(User)
+    group = models.ForeignKey(Group)
+    
+    class Meta:
+        db_table = "admin_group_relation"
+        unique_together = ("user", "group")
+
+
 class JoinGroupRequest(models.Model):
     group = models.ForeignKey(Group)
     user = models.ForeignKey(User, related_name="my_join_group_requests")