Async database with databases library in FastAPI - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the async database library.

FastAPI

from databases import [1]

Drag options to blanks, or click blank then click option'

Adatabase

BDatabase

CDatabases

Ddb

Attempts:

3 left

💡 Hint

Common Mistakes

Using lowercase 'database' instead of 'Database'.

Trying to import a non-existent module name.

The Database class is imported from the databases library to create an async database connection.

2fill in blank

medium

Complete the code to create a database connection with the URL.

FastAPI

database = Database([1])

Drag options to blanks, or click blank then click option'

A'postgresql://user:pass@localhost/dbname'

B'mysql://user:pass@localhost/dbname'

C'mongodb://localhost:27017'

D'sqlite:///test.db'

Attempts:

3 left

💡 Hint

Common Mistakes

Using SQLite URL when expecting PostgreSQL.

Using MongoDB URL which is not supported by this library.

The connection string for PostgreSQL uses the format postgresql://user:pass@host/dbname. This is the correct URL for the Database constructor.

3fill in blank

hard

Fix the error in the async function to connect to the database.

FastAPI

async def connect_db():
    await database.[1]()

Drag options to blanks, or click blank then click option'

Aopen

Bstart

Cconnect

Dconnect_db

Attempts:

3 left

💡 Hint

Common Mistakes

Using a non-existent method like 'start' or 'open'.

Calling a method that does not exist on the database object.

The Database class uses the connect() method to open the connection asynchronously.

4fill in blank

hard

Fill both blanks to create a query and fetch all rows asynchronously.

FastAPI

query = "SELECT * FROM users WHERE id = [1]"
rows = await database.[2](query)

Drag options to blanks, or click blank then click option'

A:user_id

Bfetch_all

Cexecute

D?user_id

Attempts:

3 left

💡 Hint

Common Mistakes

Using '?' instead of ':user_id' for named parameters.

Using 'execute' which runs the query but does not fetch results.

The query uses a named parameter :user_id for safe substitution. The fetch_all method retrieves all matching rows asynchronously.

5fill in blank

hard

Fill all three blanks to insert a new user asynchronously and get the inserted ID.

FastAPI

query = "INSERT INTO users(name, email) VALUES ([1], [2]) RETURNING id"
values = {"name": user_name, "email": user_email}
user_id = await database.[3](query=query, values=values)

Drag options to blanks, or click blank then click option'

A:name

B:email

Cexecute

Dfetch_one

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'execute' which runs the insert but does not return the ID for PostgreSQL.

Using positional parameters instead of named parameters.

The query uses named parameters :name and :email for safe insertion. Include RETURNING id (for PostgreSQL) and use the fetch_one method to retrieve the inserted record's ID asynchronously. The result is a dict like {'id': 1}.