Range queries for scoring in Redis - Mini Project: Build & Apply

Range Queries for Scoring in Redis

📖 Scenario: You are managing a leaderboard for a game. Players earn points, and you want to store their scores in Redis. Later, you want to find players who scored within certain ranges to reward them.

🎯 Goal: Build a Redis sorted set to store player scores, set a minimum score threshold, query players within a score range, and finally add a new player with a score.

📋 What You'll Learn

Create a sorted set called game_scores with three players and their exact scores

Create a variable called min_score and set it to 50

Use the ZREVRANGEBYSCORE command to get players with scores between 100 and min_score

Add a new player player4 with score 75 to the game_scores sorted set

💡 Why This Matters

🌍 Real World

Leaderboards in games or apps often use Redis sorted sets to store and query user scores efficiently.

💼 Career

Understanding Redis sorted sets and range queries is valuable for backend developers working on real-time scoring, ranking, or recommendation systems.

1

Create the sorted set with initial player scores

Create a Redis sorted set called game_scores and add these exact members with scores: player1 with 120, player2 with 90, and player3 with 60.

Redis

# Add players to the sorted set game_scores
# Your code here

Need a hint?

Use the ZADD command with the sorted set name, followed by score and member pairs.

2

Set the minimum score threshold

Create a variable called min_score and set it to 50.

Redis

ZADD game_scores 120 player1 90 player2 60 player3
# Set min_score variable
# Your code here

Need a hint?

Assign the number 50 to the variable min_score.

3

Query players within the score range

Use the ZREVRANGEBYSCORE command to get players from game_scores with scores between 100 and the variable min_score. Use the syntax: ZREVRANGEBYSCORE game_scores 100 min_score.

Redis

ZADD game_scores 120 player1 90 player2 60 player3
min_score=50
# Query players with scores between 100 and min_score
# Your code here

Need a hint?

Use ZREVRANGEBYSCORE with the sorted set name and score range to get players in descending order.

4

Add a new player with a score

Add a new player called player4 with a score of 75 to the game_scores sorted set using the ZADD command.

Redis

ZADD game_scores 120 player1 90 player2 60 player3
min_score=50
ZREVRANGEBYSCORE game_scores 100 50
# Add player4 with score 75
# Your code here

Need a hint?

Use ZADD with the sorted set name, score, and member name to add the new player.