Why was Alembic used in the FastAPI project, and were there any direct SQL queries to the database?

Alembic is used in FastAPI projects for database migration management — that is, for automatically creating, modifying, and rolling back database schemas in a controlled manner. This is especially important during project development when the table structure changes.

Direct SQL queries can be used in the project, but more often an ORM (such as SQLAlchemy) is used, which allows working with the database through Python objects. Alembic is closely integrated with SQLAlchemy and generates migrations based on model changes.

Thus, Alembic provides convenient and safe management of the database schema, while direct SQL queries can be used for complex or specific operations that are difficult to express through ORM.