Geo-proximity with sorted sets in Redis - Mini Project: Build & Apply

Geo-proximity with sorted sets

📖 Scenario: You are building a simple location-based service that stores places with their geographic coordinates. You want to find places near a specific location.

🎯 Goal: Create a Redis sorted set to store places with their longitude and latitude. Then, configure a radius distance. Next, query the sorted set to find places within that radius sorted by distance. Finally, complete the setup to return the results with distances.

📋 What You'll Learn

Create a sorted set called places with three places and their longitude and latitude using GEOADD.

Create a variable radius set to 10 kilometers.

Use GEORADIUS command on places with center longitude 13.361389 and latitude 38.115556, radius radius, unit km, and sort results by distance ascending.

Add the option to return distances with the results.

💡 Why This Matters

🌍 Real World

Location-based services like finding nearby restaurants, stores, or landmarks use geo-proximity queries to provide relevant results to users.

💼 Career

Understanding Redis geo commands is useful for backend developers working on location-aware applications, improving user experience with fast and efficient geographic queries.

1

Create the sorted set with places

Use the GEOADD command to add these three places to a sorted set called places with their exact longitude and latitude: Palermo (13.361389, 38.115556), Catania (15.087269, 37.502669), and Messina (15.550000, 38.193000).

Redis

# Use GEOADD to add Palermo, Catania, and Messina to 'places'
# Your code here

Need a hint?

Use GEOADD places longitude latitude member format for each place.

2

Set the radius variable

Create a variable called radius and set it to 10 to represent 10 kilometers.

Redis

GEOADD places 13.361389 38.115556 Palermo 15.087269 37.502669 Catania 15.550000 38.193000 Messina
# Set radius variable to 10
# Your code here

Need a hint?

Use SET radius 10 to create the variable.

3

Query places within radius sorted by distance

Use the GEORADIUS command on places with center longitude 13.361389 and latitude 38.115556, radius radius, unit km, and sort the results by distance ascending using ASC.

Redis

GEOADD places 13.361389 38.115556 Palermo 15.087269 37.502669 Catania 15.550000 38.193000 Messina
SET radius 10
# Use GEORADIUS to find places within radius sorted by distance ascending
# Your code here

Need a hint?

Use GEORADIUS places longitude latitude radius km ASC to get sorted results.

4

Return distances with the results

Add the WITHDIST option to the GEORADIUS command to return the distances along with the place names.

Redis

GEOADD places 13.361389 38.115556 Palermo 15.087269 37.502669 Catania 15.550000 38.193000 Messina
SET radius 10
GEORADIUS places 13.361389 38.115556 10 km ASC
# Add WITHDIST option to return distances
# Your code here

Need a hint?

Add WITHDIST after ASC in the GEORADIUS command.