Embedding vs referencing in Redis - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to store a user profile with embedded address data in Redis using a hash.

Redis

HSET user:1000 name "Alice" [1] "123 Main St" city "Springfield"

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

Astreet

Baddress

Clocation

Daddr

Attempts:

3 left

💡 Hint

Common Mistakes

Using a generic term like 'address' which might be confusing in a hash.

Using abbreviations that are unclear.

The key 'street' is used to embed the street address directly in the user hash.

2fill in blank

medium

Complete the code to reference an address stored separately by its ID in Redis.

Redis

HSET user:1001 name "Bob" address_id [1]

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

Aaddress:200

Baddr200

Caddress_200

Daddr:200

Attempts:

3 left

💡 Hint

Common Mistakes

Using keys without colon separators which is less common in Redis.

Using inconsistent naming conventions.

The field 'address_id' holds a reference key 'address:200' pointing to the separate address hash.

3fill in blank

hard

Fix the error in the code that tries to embed a list of phone numbers directly in a Redis hash.

Redis

HSET user:1002 name "Carol" phones [1]

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

A"[123-4567, 234-5678]"

B"123-4567;234-5678"

C"123-4567,234-5678"

D"123-4567 234-5678"

Attempts:

3 left

💡 Hint

Common Mistakes

Using JSON-like arrays which Redis hashes do not support.

Using semicolons or spaces which are less standard separators.

Redis hashes store strings, so phone numbers should be stored as a comma-separated string without brackets.

4fill in blank

hard

Fill in the blank to create a Redis command that retrieves the city from the referenced address hash.

Redis

HGET [1] city

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

Aaddress_300

Baddress:300

Cuser:city

Duser:300

Attempts:

3 left

💡 Hint

Common Mistakes

Using the user key instead of the address key.

Using underscores instead of colons in keys.

The command retrieves the 'city' field from the address hash with key 'address:300'.

5fill in blank

hard

Fill all three blanks to create a Redis Lua script snippet that fetches a user name, then fetches the city from the referenced address hash.

Redis

local userKey = [1]
local addressKey = redis.call('HGET', userKey, [2])
return redis.call('HGET', addressKey, [3])

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

A'user:400'

B'address_id'

C'city'

D'name'

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong field names like 'name' instead of 'address_id' for the reference.

Mixing up the order of commands.

The script first sets the user key, then gets the 'address_id' field from the user hash, and finally retrieves the 'city' from the address hash.