Angular 2+ with Django Rest Framework tutorial (Part 3): Create database models

Angular 2+ with Django Rest Framework tutorial (Part 3): Create database models

This is part 3 of our tutorial series to learn how to use Django Rest Framework with Angular 2+ by building a simple product inventory manager .

Django REST framework (DRF) with Angular 2+ tutorial (Part 1)

Django REST framework (DRF) with Angular 2+ tutorial (Part 2)

Django REST framework (DRF) with Angular 2+ tutorial (Part 3)

On the first part we have installed Django and created the server side project .

On the second part we have installed Angular 2+ and created the client side project .

In this part we are going to create a Django app and database models .

Creating the Django app

Lets start by creating a Django app so head over to your terminal and enter :

cd ProductInventoryManager 
python manage.py startapp core

Then open your project settings.py and add this app to the list of installed apps 

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'rest_framework',
    'core'
]

Now we are ready to add database models .

Open core/models.py and get ready to add models .

Creating database models

Users can create products ,families ,locations and add transactions .A product belongs to a family of products and has a location .To move products out or in the stock we use make a transaction .

A Family has these attributes : reference , title and description .

class Family(models.Model):

    reference = models.CharField(max_length=13, help_text="Enter Family Reference")
    title = models.CharField(max_length=200, help_text="Enter Family Title")
    description = models.TextField(help_text="Enter Family Description")

    unit = models.CharField(max_length=10,help_text="Enter Family Unit ")

    minQuantity = models.FloatField(help_text="Enter Family Min Quantity")

    def get_absolute_url(self):
        """
        Returns the url to access a particular instance of Family.
        """
        return reverse('family-detail-view', args=[str(self.id)])

    def __str__(self):

        return self.title

A Location has these attributes : reference , title and description .

class Location(models.Model):

    reference = models.CharField(max_length=20, help_text="Enter Location Reference")
    title = models.CharField(max_length=200, help_text="Enter Location Title")
    description = models.TextField(help_text="Enter Location Description")

    def get_absolute_url(self):
        """
        Returns the url to access a particular instance of Location.
        """
        return reverse('family-detail-view', args=[str(self.id)])

    def __str__(self):

        return self.title

A Product has these attributes : Title ,Description ,Unit Price ,SKU (Stock Keeping Unit) , Barcode (ISBN, UPC etc.) ,Quantity ,minQuantity ,Unit .

class Product(models.Model):

    sku = models.CharField(max_length=13,help_text="Enter Product Stock Keeping Unit")
    barcode = models.CharField(max_length=13,help_text="Enter Product Barcode (ISBN, UPC ...)")

    title = models.CharField(max_length=200, help_text="Enter Product Title")
    description = models.TextField(help_text="Enter Product Description")

    unitCost = models.FloatField(help_text="Enter Product Unit Cost")
    unit = models.CharField(max_length=10,help_text="Enter Product Unit ")

    quantity = models.FloatField(help_text="Enter Product Quantity")
    minQuantity = models.FloatField(help_text="Enter Product Min Quantity")

    family = models.ForeignKey('Family')
    location = models.ForeignKey('Location')

    def get_absolute_url(self):
        """
        Returns the url to access a particular instance of Product.
        """
        return reverse('product-detail-view', args=[str(self.id)])

    def __str__(self):

        return self.title

A Transaction has these attributes : Date , Quantity , Unit Cost , Reason (New Stock - Usable Return - Unusable Return ) ,UPC (Universal Product Code ) ,Comment .

class Transaction(models.Model):

    sku = models.CharField(max_length=13,help_text="Enter Product Stock Keeping Unit")
    barcode = models.CharField(max_length=13,help_text="Enter Product Barcode (ISBN, UPC ...)")

    comment = models.TextField(help_text="Enter Product Stock Keeping Unit")

    unitCost = models.FloatField(help_text="Enter Product Unit Cost")

    quantity = models.FloatField(help_text="Enter Product Quantity")

    product = models.ForeignKey('Product')

    date = models.DateField(null=True, blank=True)

    REASONS = (
        ('ns', 'New Stock'),
        ('ur', 'Usable Return'),
        ('nr', 'Unusable Return'),
    )


    reason = models.CharField(max_length=2, choices=REASONS, blank=True, default='ns', help_text='Reason for transaction')

    def get_absolute_url(self):
        """
        Returns the url to access a particular instance of Product.
        """
        return reverse('transaction-detail-view', args=[str(self.id)])

    def __str__(self):

        return 'Transaction :  %d' % (self.id)

Now you should be able to migrate your database to create actual tables .

Head over to your terminal and enter :

python manage.py makemigrations 
python manage.py migrate

Conclusion

This is the end of the part 3 .We have created a Django app and different Django models for our simple product inventory manager based on Angular 2+ and Django Rest Framework .

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