Write-through pattern in Redis - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to set a key-value pair in Redis cache.

Redis

redis_client.[1]('user:1', 'Alice')

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

Aset

Bget

Cdelete

Dexists

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'get' instead of 'set' to store data.

The set command stores a key-value pair in Redis.

2fill in blank

medium

Complete the code to update the database after setting the cache in write-through pattern.

Redis

database.[1]('UPDATE users SET name = %s WHERE id = %s', ('Alice', 1))

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

Acommit

Bfetch

Cexecute

Dselect

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'fetch' which is for retrieving data, not updating.

The execute method runs the SQL update command on the database.

3fill in blank

hard

Fix the error in the write-through update code by completing the missing Redis command.

Redis

def write_through_update(key, value):
    redis_client.[1](key, value)
    database.execute('UPDATE users SET name = %s WHERE id = %s', (value, 1))
    database.commit()

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

Aset

Bget

Cdelete

Dexists

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'get' which only reads data, not updates.

To update the cache in write-through, use set to write the new value.

4fill in blank

hard

Fill both blanks to complete the write-through pattern: update cache and then update database.

Redis

def write_through_update(key, value):
    redis_client.[1](key, value)
    database.[2]('UPDATE users SET name = %s WHERE id = %s', (value, 1))
    database.commit()

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

Aset

Bexecute

Cget

Dfetch

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping 'set' and 'execute' commands.

First, use set to update Redis cache, then execute to update the database.

5fill in blank

hard

Fill all three blanks to implement a write-through update: set cache key, execute DB update, and commit transaction.

Redis

def write_through_update(key, value):
    redis_client.[1](key, value)
    database.[2]('UPDATE users SET name = %s WHERE id = %s', (value, 1))
    database.[3]()

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

Aget

Bexecute

Ccommit

Dset

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting to commit the database transaction.

Use set to update cache, execute to run the SQL update, and commit to save changes in the database.