The database design rbac component (a)

rbac is designed role-based permissions, contains a total of six tables, table design specific as follows:

from django.db import models

class Menu(models.Model):
    """
    菜单表
    """
    title = models.CharField(verbose_name='菜单名称',max_length=32,unique=True)
    icon = models.CharField(max_length=128, blank=True, null=True)

    def __str__(self):
        return self.title

class Permission(models.Model):
    """
    权限表
    """
    title = models.CharField(verbose_name='权限标题', max_length=32)
    URL = models.CharField (= the verbose_name ' containing canonical the URL ' , MAX_LENGTH = 128 ) 
    name = models.CharField (the verbose_name = ' URL alias ' , 64 = MAX_LENGTH, UNIQUE = True) # control authority to the button 
    parent = models.ForeignKey (= the verbose_name ' parent rights ' , to = ' Self ' , null = True, blank = True, on_delete = models.CASCADE, limit_choices_to = { ' parent__isnull ' : True}) # construct rights relationships non-menu, the default menu expand 
    menu = models.ForeignKey (the verbose_name = ' menu ' , to = ' menu ',null=True,blank=True,on_delete=models.CASCADE)

    def __str__(self):
        return self.title


class Role(models.Model):
    """
    角色
    """
    title = models.CharField(verbose_name='角色名称', max_length=32)
    permissions = models.ManyToManyField(verbose_name='拥有的所有权限', to='Permission', blank=True)


    def __str__(self):
        return self.title


classThe UserInfo (models.Model):
    "" " 
    User Table 
    " "" 
    username = models.CharField (the verbose_name = ' username ' , MAX_LENGTH = 32 ) 
    password = models.CharField (the verbose_name = ' password ' , MAX_LENGTH = 64 ) 
    In Email = models.CharField (= the verbose_name ' E-mail ' , max_length = 32 ) 
    the roles = models.ManyToManyField (verbose_name = ' has all the roles ' , to = role, blank = True) 

    class Meta:
        abstract = True # To crm user tables inherit 

    DEF  __str__ (Self):
         return self.username

Where the user and role tables are many relationships, roles and permissions table is a table-many relationship. Further authority table associated with the menu, one such privilege at a certain url mount a menu, and the associated authority table itself, so that such addition, deletion, and modification of the permissions can be hung on a url a permission url below.