If you try out a Python package in the REPL, the output of print() may not be the most useful one. In Ruby I used for this case the class PrettyPrint and as it turns out, Python has a similar built-in feature. Let's have a look.
SQLAlchemy is a massive database toolkit that you can use in various ways. Let us do a recap on the options you have and look for a good starting point for your situation.
The mapping for SQLAlchemy ORM takes a lot of initial work – often too much work for just a few queries against an existing database. However, there is an extension that offers a quicker way to work with a rudimentary object model and the nice parts of ORM.
My first steps with SQLAlchemy and SQL Server ended in a lot of problems, mainly around the driver and the correct form of the connection string. Let us look what you need to successfully connect to SQL Server.
The right index can boost the performance of your SQL query enormously while constrains help you to enforce the integrity of your data in the database. Let us look how SQLAlchemy can help us with both. I made my examples for SQLAlchemy ORM, but they work in Core as well.
SQLAlchemy and Alembic work on top of an abstraction layer and not directly on your database. This may lead to a situation in which a common feature in SQL is not implemented by your specific database system. Let us look what we must do before we can work with constraints in SQLite.
SQLAlchemy and Alembic are a great combination to keep your database in sync with your application as we saw in the last post. But what do you do when you already created some tables with SQLAlchemy that now contain data we cannot lose? Let us look how we can fix this without much extra work.
SQLAlchemy does not modify existing tables. What can we do to keep our database in sync with our application?
SQLAlchemy ORM does a lot of magic in the background when we ask it to fetch data from our database. It is time to take a closer look how SQLAlchemy loads our data and what can go wrong if we are not careful.
The higher abstraction of SQLAlchemy ORM allows us to work with our objects as we usually do in Python. We do not need to think much about tables and relationships – SQLAlchemy ORM does this work for us.