15.2. Models in Django: Structure of a Django project

Página 76

Django is a Python web development framework that follows the Model-View-Controller (MVC) pattern. It was designed to help developers build complex web applications with less code and in a shorter amount of time. One of the main components of Django is the model system, which is the data abstraction layer that allows you to manipulate the database in a more intuitive and secure way.

Structure of a Django project

A Django project is made up of one or more applications, which are self-contained modules that represent specific application functionality. Each application contains a set of models, views, templates, and other code needed to implement that functionality.

When you create a new Django project using the django-admin startproject command, Django creates a directory and file structure that includes:

• manage.py: A command-line utility that lets you interact with the Django project in a variety of ways, such as starting a development server, creating new applications, or executing management commands.
li>
• settings.py: a configuration file where you can define various project options, such as the database to be used, installed applications, middleware settings, and others.
li>
• urls.py: A file that defines the URL routes for the project. Each URL can be mapped to a specific view, which is a function or class that processes the request and returns a response.
• wsgi.py or asgi.py: files that define the web server gateway interface (WSGI) or asynchronous server gateway interface (ASGI) for the project. They are used to serve the project on a production server.

Templates in Django

In Django, a model is the representation of a database entity. Each model is a Python class that inherits from django.db.models.Model and defines a set of fields and methods that represent the columns of the table and the operations that can be performed on it.

Each field is represented by an instance of a subclass of django.db.models.Field, such as CharField for short strings, TextField for long strings, IntegerField for integers, DateTimeField for dates and times, and so on. Each field can have several arguments to specify its behavior, such as max_length for the maximum number of characters, default for the default value, unique to indicate that values ​​must be unique, and others.

Templates can also define methods for performing database operations, such as saving a record, deleting a record, fetching records, and so on. In addition, they can define custom methods to implement application-specific business logic.

Once the models are defined, Django can automatically create the corresponding database tables using the command python manage.py makemigrations to create the migrations (which are files that describe the changes to be made to the database) and python manage.py migrate to apply the migrations.

In addition, Django provides a high-level database API that lets you perform CRUD (create, read, update, delete) operations easily and securely without having to write SQL directly. For example, you can create a new record using the save() method of the model, fetch records using the filter() method of the model manager, update records by modifying the attributes from the model and calling the save() method again, and delete records using the delete() method of the model.

Conclusion

In short, Django is a Python web development framework that provides a robust, easy-to-use architecture for creating complex web applications. The structure of a Django project is made up of several independent applications, each containing its own models, views, templates, and other code. Models in Django are a high-level abstraction of the database that allow you to manipulate it more intuitively and securely.

Next page of the Free Ebook:

7715.3. Templates in Django: Templates in Django