Async database queries in FastAPI - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does 'async' mean in async database queries?

It means the program can start a database query and do other work while waiting for the query to finish, making the app faster and more responsive.

beginner

Why use async database queries in FastAPI?

Because FastAPI supports async code, using async queries helps handle many users at once without slowing down the app.

intermediate

Which Python library is commonly used for async database queries with FastAPI?

Databases like the 'databases' library or async drivers like 'asyncpg' for PostgreSQL are common choices.

beginner

How do you define an async function in FastAPI to query the database?

Use 'async def' before the function name and 'await' before the database call to wait for the result without blocking.

beginner

What is the benefit of using 'await' in async database queries?

'await' pauses the function until the query finishes but lets other tasks run meanwhile, improving app speed.

In FastAPI, what keyword marks a function as asynchronous?

A async

B await

C def

D sync

'async' before 'def' marks the function as asynchronous.

Which keyword is used to wait for an async database query to complete?

A wait

B async

C await

D pause

'await' pauses the function until the async operation finishes.

Why are async database queries faster in handling many users?

A They let the server do other work while waiting for queries.

B They block the server until queries finish.

C They run queries in parallel threads.

D They cache all queries automatically.

Async queries let the server handle other tasks while waiting, improving concurrency.

Which library is NOT typically used for async database queries in FastAPI?

A databases

B requests

C asyncpg

D SQLAlchemy with async support

'requests' is for HTTP calls, not async database queries.

What happens if you forget to use 'await' before an async database call?

A The query runs synchronously.

B The query runs twice.

C The app crashes immediately.

D The function returns a coroutine, not the result.

Without 'await', you get a coroutine object instead of the query result.

Explain how async database queries improve performance in FastAPI applications.

Think about what happens when the app waits for the database.

Describe the steps to write an async function in FastAPI that queries a database.

Focus on function syntax and waiting for the query.