ZRANGEBYSCORE for score-based queries in Redis - Mini Project: Build & Apply

Using ZRANGEBYSCORE for Score-Based Queries in Redis

📖 Scenario: You are managing a leaderboard for a game. Players have scores stored in a Redis sorted set. You want to find players within certain score ranges.

🎯 Goal: Build Redis commands step-by-step to add players with scores and query players by score ranges using ZRANGEBYSCORE.

📋 What You'll Learn

Create a sorted set called leaderboard with exact player-score pairs

Set a minimum score variable called min_score with a specific value

Use ZRANGEBYSCORE to get players with scores between min_score and a maximum score

Add a final command to get players with scores in a different range including limits

💡 Why This Matters

🌍 Real World

Leaderboards, ranking systems, and any application where you need to find items within score ranges quickly.

💼 Career

Understanding sorted sets and score-based queries is essential for roles involving Redis, caching, and real-time data processing.

1

DATA SETUP: Create the leaderboard sorted set

Add these exact players and scores to a Redis sorted set called leaderboard: "Alice" with score 50, "Bob" with score 70, "Charlie" with score 60, "Diana" with score 80, and "Eve" with score 90. Use the ZADD command for each player.

Redis

# Your Redis commands here to add players to leaderboard

Need a hint?

Use ZADD leaderboard score player for each player.

2

CONFIGURATION: Set the minimum score variable

Set a variable called min_score to the value 60. This will be used to filter players with scores greater than or equal to 60.

Redis

ZADD leaderboard 50 Alice
ZADD leaderboard 70 Bob
ZADD leaderboard 60 Charlie
ZADD leaderboard 80 Diana
ZADD leaderboard 90 Eve

# Set min_score variable

Need a hint?

Assign 60 to min_score like min_score=60.

3

CORE LOGIC: Query players with scores between min_score and 80

Use the ZRANGEBYSCORE command to get players from the leaderboard with scores between min_score and 80. Use the exact command format: ZRANGEBYSCORE leaderboard min_score 80.

Redis

ZADD leaderboard 50 Alice
ZADD leaderboard 70 Bob
ZADD leaderboard 60 Charlie
ZADD leaderboard 80 Diana
ZADD leaderboard 90 Eve

min_score=60

# Use ZRANGEBYSCORE to get players with scores between min_score and 80

Need a hint?

Use ZRANGEBYSCORE leaderboard 60 80 to get players with scores from 60 to 80.

4

COMPLETION: Query players with scores between 70 and 90 with limit

Add a ZRANGEBYSCORE command to get players from leaderboard with scores between 70 and 90, but only return the first 2 players. Use the syntax: ZRANGEBYSCORE leaderboard 70 90 LIMIT 0 2.

Redis

ZADD leaderboard 50 Alice
ZADD leaderboard 70 Bob
ZADD leaderboard 60 Charlie
ZADD leaderboard 80 Diana
ZADD leaderboard 90 Eve

min_score=60

ZRANGEBYSCORE leaderboard 60 80

# Add ZRANGEBYSCORE with LIMIT to get first 2 players with scores 70 to 90

Need a hint?

Use ZRANGEBYSCORE leaderboard 70 90 LIMIT 0 2 to get the first two players in that score range.