[Django] Models with django-mssql

 Python    Django    Django MSSQL 

  

(From Django MSSQL)

▌Introduction

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We will integrate Django MSSQL and Django for creating tables and columns in Sql server by Django Models.

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[Django] Queries – Create form with ModelForm

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▌Environment

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▋Python 3.6.2

▋Django 1.8.18

▌Implement

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▋Install packages

From Django MSSQL document, we can see the dependencies.

▋Django downgrade (Optional)

Notice that the latest release only support Django 1.8.X

Use this command to install the latest version of 1.8.X

$ python -m pip install "Django~=1.8.0"

PS. The ~= syntax means that we are going to install the latest release on 1.8.X.

▋Django MSSQL

$ python -m pip install django-mssql

▋pypwin32

$ python -m pip install pypiwin32

Here is my pip list.

▋Models

The db schema will be looked like this.
[Products].[ProdTypeId] is a foreign key of [ProductTypes].

Open models.py in your app.

▋models.py

from django.db import models

class Product(models.Model):

    Id = models.IntegerField(primary_key=True)

    Price = models.IntegerField(null=False)

    Title = models.CharField(max_length=100, null=False)

    ProdTypeId = models.ForeignKey('ProductType', db_column='ProdTypeId', related_name='Products_ProductTypes')

    def __str__(self):

        return self.Title

    class Meta(object):

        db_table = "Products"

class ProductType(models.Model):

    Id = models.IntegerField(primary_key=True)

    Name = models.CharField(max_length=50, null=False)

    def __str__(self):

        return self.Name

 

    class Meta(object):

        db_table = "ProductTypes"

1.

   

class Meta(object):

        db_table = "Products"

db_table is an option for setting the table name of this model.

2.

ProdTypeId = models.ForeignKey('ProductType', db_column='ProdTypeId', related_name='Products_ProductTypes')

This line from model: Product, will create a foreign key to model: ProductType.

db_column:
Set the column name for this foreign key.

related_name:

The name to use for the relation from the related object back to this one.

▋Database connection information

Go to settings.py, update the DATABASES configuration as following.

▋settings.py

DATABASES = {

    'default': {

        'ENGINE': 'sqlserver_ado',

        'HOST':'{Server name/IP}',

        'NAME': '{db name}',

        'USER':'{user}',

        'PASSWORD':'{pwd}',

        'PORT':'1433',

        'OPTIONS':{

            'provider':'SQLOLEDB'       

}

    },

}

▋Update installed app

Before we do the database migration, we have to update the installed app.

▋settings.py

# Application definition

INSTALLED_APPS = [

    'app', #PUT you app name here

    'django.contrib.admin',

$

    'django.contrib.contenttypes',

    'django.contrib.sessions',

    'django.contrib.messages',

    'django.contrib.staticfiles',

]

▋Database migration

First, create a migration.

$ python manage.py makemigrations {app}

Which {app} is your app name.

We can find the migration file in app/migrations

Let’s start migrating the database.

$ python manage.py migrate {app}

▋Check it up!

Lets see if the migration works.

▋Tables

▋Enabled migration history

▋Products and ProductTypes

▌Github

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▌Reference

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▋Django MSSQL: Installation

▋Django MSSQL: Datatypes

▋djangogirlstaipei.gitbooks.io

▋Stackoverflow: no module named pythoncom

▋Stackoverflow: differentiate null=True, blank=True in django

▋Stackoverflow: What is “related_name” used for in Django?