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Unless you are creating a simple website, there is little chance of avoiding the need to interact with some form of database when building modern web applications. Unfortunately, this usually means you have to get your hands dirty with Structured Query Language (SQL)—which is just about nobody’s idea of fun. In Django, the messy issues with SQL is a solved problem: you don’t have to use SQL at all unless you want to. Instead, you use a Django (ORM) to the underlying database.
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ORM is a powerful programming technique that makes working with data and relational databases much easier. Most common databases are programmed with some form of SQL, but each database implements SQL in its own way. SQL can also be complicated and difficult to learn.
An ORM tool simplifies database programming by providing a simple mapping between an object (the ‘O’ in ORM) and the underlying database. This means the programmer need not know the database structure, nor does it require complex SQL to manipulate and retrieve data (Figure 4-1). Figure 4-1: An ORM allows for simple manipulation of data without having to write complex SQL.
In Django, the model is the object mapped to the database. When you create a model, Django executes SQL to create a corresponding table in the database (Figure 4-2) without you having to write a single line of SQL. Django prefixes the table name with the name of your Django application. The model also links related information in the database. Figure 4-2: Creating a Django model creates a corresponding table in the database.
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In Figure 4-3, a second model keeps track of a user’s course enrollments. This is a simplification, but is a handy overview of how Django’s ORM uses the model data to create database tables. We will dig much deeper into models shortly, so don’t worry if you don’t 100% understand what is going on right now. Things become clearer once you have had the chance to build actual models.
Django officially supports five databases: There are also several third-party applications available if you need to connect to an unofficially supported database. The preference for most Django developers, myself included, is Postgre SQL. My SQL is also a common database backend for Django.
Installing and configuring a database is not a task for a beginner. Luckily, Django installs and configures SQLite automatically, with no input from you, so we will use SQLite in this book. Next easiest answer—Oracle is for big corporations with deep pockets.
I cover running your project with Postgre SQL, My SQL and Maria DB in Chapter 16. Easy one first—SQLite is for early development and testing. You are unlikely to need to decide whether to use Oracle unless you join a big enterprise, and then you might find it’s your only choice. As for Postgre SQL, Maria DB (Django 3) and My SQL, there are specific reasons Postgre SQL is a better database than My SQL. However, by the time you have learned enough programming to understand why, you can judge for yourself.
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Most often, you don’t get a choice because the client, your employer or the web host makes it for you. Smart programmers avoid this kind of argument—use Postgre SQL if you can; otherwise, My SQL is fine too. Maria DB is the new kid on the Django block, with support only added with the release of Django 3.0, so I have no advice at this time. Django’s models are written in Python and provide a mapping to the underlying database structure. Django uses a model to execute SQL behind the scenes to return Python data structures—which Django calls management command. We’ll be diving deeper into introspecting existing databases in Chapter 16. Now you have an idea what Django models are, it’s time to create your first model.
The My Club website application includes an event planner. This is an excellent tool for checking out what is going on inside your SQLite database as Django changes things. If you want to install DB Browser for SQLite on your machine, you can download it from There is lots of information we can record for a club event, but we will start with a basic event model.