Python Django

When you use SQLite3 as your Django application backend database, you may need to change or even drop tables from the SQLite3 database. This article will tell you how to do that.

When you develop a Django app, you always need to change the model fields. But how to make the changes take effect (add/remove table column to/from backend database table ). To a beginner, this question may be confused. This article will tell you how to do it.

You have learnd how to use Django model manager’s filter or exclude method to get query result data in article Django Simple CRUD Operation Example. To use filter method is so easy as below. Department.objects.filter(dept_desc__contains=’dev2qa’) <QuerySet [<Department: Development,Develop dev2qa.com website use Django>]> We can see that the filter function’s argument is dept_desc__contains=’dev2qa’, i think this is not difficult

We all know that model data operation in Django is so easy, you do not need to write any sql command at all, what you need to do is just use model class’s attribute objects ‘s methods to create, query, update and delete mode data records in backend database table like below. Suppose our model

During the process of developing the example code in the article Django Bootstrap3 Example, when I change the model class source code ( for example add a new field ), I always want to migrate the changes to the backend database table immediately. But I found sometimes the migration does not take effect when the

This example is based on the article Django Bootstrap3 Example, it reuse the Department and Employee model class. Suppose Department and Employee model are many to many relationships, that means one department can have multiple employees and one employee can belong to multiple departments. Then we need to do the following changes.

In the previous article How To Add Models To Django Admin Site, we have learned how to manage your Django app’s model data in the Django project admin website. But even we implement the model class’s __str__(self) function, we can only display one model class column in the project admin site like the below picture.

When you create a Django project and start the project built-in web server successfully, it also contains an admin website in this project. This admin website is the result of django.contrib.admin and django.contrib.auth Django applications. The Django project installed some default applications in the project settings.py file when you create it. You can find them in the INSTALLED_APPS section

Django model class is defined in models.py file in Django application folder, each model class will be mapped to a database table in the project backend database server. After you define the model class, you can create the related table use Django manage.py tasks command, all the low level sql command ( such as table

We have learnt how to create and run unit test in Django project in previous article Django Unit Test Example. But that example mainly focus on Django application models test. Django also provide class django.test.Client for you to test your Django application views. This example will tell you how to use it.