SQLAlchemy setup with FastAPI - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is SQLAlchemy used for in FastAPI?

SQLAlchemy is used to manage database operations in FastAPI. It helps connect to the database, define tables as Python classes, and perform queries easily.

beginner

What is the purpose of the SessionLocal in SQLAlchemy setup with FastAPI?

SessionLocal creates a new database session for each request. It manages the connection and ensures changes are saved or rolled back properly.

beginner

Why do we use Base = declarative_base() in SQLAlchemy?

It creates a base class for all database models. Models inherit from <code>Base</code> to define tables and columns in the database.

intermediate

How do you ensure the database session is closed after a FastAPI request?

Use a dependency with yield to provide the session and close it after the request finishes. This avoids leaving open connections.

beginner

What is the role of engine = create_engine() in SQLAlchemy setup?

The engine connects SQLAlchemy to the actual database. It manages the database URL and handles communication between Python and the database.

Which SQLAlchemy component defines the structure of database tables?

A FastAPI app instance

B Base class from declarative_base()

C create_engine()

D SessionLocal

The Base class from declarative_base() is used to create models that define tables and columns.

What does the SessionLocal object do in FastAPI with SQLAlchemy?

A Creates a new database session per request

B Defines database tables

C Starts the FastAPI server

D Handles HTTP requests

SessionLocal manages database sessions, creating one for each request.

How do you properly close a database session in FastAPI?

A Use a dependency with yield to close after request

B Call session.close() manually in every route

C Let Python garbage collector handle it

D No need to close sessions

Using a dependency with yield ensures the session closes automatically after the request.

What is the purpose of create_engine() in SQLAlchemy?

A Create HTTP responses

B Define API routes

C Connect to the database

D Manage user sessions

create_engine() sets up the connection to the database.

Which of these is NOT part of a typical SQLAlchemy setup in FastAPI?

A declarative_base()

B SessionLocal

C create_engine()

D React components

React components are unrelated to SQLAlchemy or FastAPI backend setup.

Explain the steps to set up SQLAlchemy with FastAPI for database access.

Think about how you connect, define tables, and manage sessions.

Describe how you use a database session safely in FastAPI routes.

Focus on lifecycle of session during a request.