Repository pattern for data access in Flask - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a repository class for accessing user data.

Flask

class UserRepository:
    def __init__(self, db_session):
        self.db_session = [1]

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

Adb_session

Bsession

Cdatabase

Ddb

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different variable name than the constructor parameter.

Forgetting to assign the parameter to an instance variable.

The repository class stores the database session passed during initialization as db_session to use for data operations.

2fill in blank

medium

Complete the method to add a new user object to the database session.

Flask

def add_user(self, user):
    self.db_session.[1](user)

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Aadd

Bsave

Cinsert

Dcommit

Attempts:

3 left

💡 Hint

Common Mistakes

Using commit instead of add.

Using insert which is not a session method.

To add a new object to the session in SQLAlchemy, use the add method.

3fill in blank

hard

Fix the error in the method to retrieve a user by ID using the session's query.

Flask

def get_user_by_id(self, user_id):
    return self.db_session.query(User).[1](user_id)

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Afilter_by

Bget

Cfilter

Dfind

Attempts:

3 left

💡 Hint

Common Mistakes

Using filter_by without calling .first().

Using a non-existent method like find.

The get method fetches an object by primary key directly, which is efficient and correct here.

4fill in blank

hard

Fill both blanks to update a user's email and commit the change.

Flask

def update_user_email(self, user_id, new_email):
    user = self.db_session.query(User).get(user_id)
    user.email = [1]
    self.db_session.[2]()

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Anew_email

Bcommit

Cflush

Demail

Attempts:

3 left

💡 Hint

Common Mistakes

Assigning the wrong variable to user.email.

Calling flush instead of commit.

Assign the new email to the user's email attribute, then call commit to save changes.

5fill in blank

hard

Fill all three blanks to delete a user by ID and commit the transaction.

Flask

def delete_user(self, user_id):
    user = self.db_session.query(User).[1](user_id)
    if user:
        self.db_session.[2](user)
        self.db_session.[3]()

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

Aget

Bdelete

Ccommit

Dfilter_by

Attempts:

3 left

💡 Hint

Common Mistakes

Using filter_by without fetching the object.

Calling commit before deleting.

Retrieve the user by primary key with get, delete the user object, then commit the session.