Django -Marathon 3/6

How to create a object in Django ?

• -          import django
• -          django.setup()
• -          from app.models import Artist
• -          newArtist=Artist(name =”Artist Name ”,year_formed=2015);
• -          newArtist.save();

-          // Save Function is inherited in the model class

-          // check migrations carefully if save is not working  ‘

Updating an Object

• -          newArtist.name="Maroon"
• -          newArtist.save()

Queries in Django 

-         

>>> allArtist=Artist.objects.all() [.all() to get all records  ]

>>> allArtist[0].name

>>> allArtist[0].ID

>>> altArtist=Artist.objects.get(id=1) [Use try catch in get for exception]

>>> altArtis[0]

Using Basic Filter Statement in the “get” Statement 

>>> console=Artist.objects.get(name="Maroon")

>>> print (console.id)

Using filter on the objects

>>> console=Artist.objects.filter(name__startswith="M")

// ‘I’ for case insensitive search 

>>> console=Artist.objects.filter(name__istartswith="M")

// using exact match in the data

>>> console=Artist.objects.filter(name__exact="Maroon")

>>> console=Artist.objects.filter(name__iexact="Maroon")

// Displaying multiple Query results using for Loop 

>>> for artist in console:

...     print(artist.name)

// Using multiple filter restrictions conditions in the ORM query  ‘.’ 

Operator

>>> console=Artist.objects.filter(name__iexact="Maroon").filter(year_formed=2015)

>>> console=Artist.objects.filter(name__iexact="Maroon").exclude(year_formed=2015)

// using Foreign Key  for connecting two tables [Join Statements]

>>> Album(name="Up",artist=allArtist[0]).save()

>>> Album(name="down",artist=allArtist[0]).save()

>>> newAlbum=Album.objects.get.all()

Where allArtist is an instance OF THE CLASS Artist , Inserting foreign key elements by referring them to the instance of another class 

>>> for storage in newAlbum:

...     print(storage.id,storage.name)