Many-table structure design:

Models django.db Import from 
# the Create your Models here Wallpaper. 
class Publisher (models.Model): 
    name = models.CharField (MAX_LENGTH = 32) 
    DEF __str __ (Self): 
        return the self.name 

class Book (models.Model): 
    name = models.CharField (MAX_LENGTH = 32) 
    Pub = models.ForeignKey (Publisher, on_delete = models.CASCADE,) 
    DEF __str __ (Self): 
        return the self.name 

    "" " 
    on_delete version 2.0 is required after the 
    on_delete = 
        models.CASCADE cascade delete 
        PROTECT protecting 
        the sET (1)     
        set_default set as the default value for a certain value 
        SET_NULL set to null 
        DO_NOTHING change anything 
    . "" "

the Author class (models.Model): 
    name = models.CharField (MAX_LENGTH = 32) 
    Books = models.ManyToManyField ( 'Book') # does not generate a column of a table generated 

# class AuthorBook (models.Model): 
# = author models.ForeignKey (Author) 
# = models.ForeignKey Book (Book)