Django Relational Object Mapping (Object relational Mapping, short ORM)

Model

• Create databases, Design table structures and fields

Django follows code Frist: automatically generate database tables based on classes defined in your code

 from Import Models    class UserInfo (models. Model):    = models. Charfield (max_length=30)    = models. Emailfield ()    = models. TextField ()

Even table structure

• One-to-many: models. ForeignKey (Other tables)
• Many-to-many: models. Manytomanyfield (Other tables)
• One to one: models. Onetoonefield (Other tables)

Action table

 #Increase        #models. Tb1.objects.create (c1= ' xx ', c2= ' oo ') adds a piece of data that can accept the dictionary type data **kwargs    #obj = models. TB1 (c1= ' xx ', c2= ' oo ')    #Obj.save ()    #Check    #    #models. Tb1.objects.get (id=123) # Get a single piece of data that doesn't exist then an error (not recommended)    #models. Tb1.objects.all () # Get all    #models. Tb1.objects.filter (Name= ' seven ') # gets the data for the specified condition    #Delete    #    #models. Tb1.objects.filter (Name= ' seven '). Delete () # Deletes data for the specified condition    #Change    #models. Tb1.objects.filter (Name= ' seven '). Update (gender= ' 0 ') # Updates the data for the specified criteria, all supported **kwargs    #obj = models. Tb1.objects.get (id=1)    #obj.c1 = ' 111 '    #Obj.save () # Modify a single piece of data

Django Relational Object Mapping (Object relational Mapping, short ORM)