Elements are automatically **sorted** by their **score**, allowing for efficient **sorting** and **retrieval operations**.


The **image** illustrates a Redis **sorted set**, where **elements** are ordered by their numeric **score**. Each **element** is unique and paired with a **score** that determines its **position** in the set.

# Key Commands
To **add** an element to a **sorted set**, use the `ZADD` **command**. If the element already **exists**, its score is **updated**. To **remove** an element, use the `ZREM` **command**.

```
ZADD leaderboard 1000 player1
ZADD leaderboard 1200 player1  # updates the score
ZREM leaderboard player2       # removes an element
```

To **retrieve** elements with their **scores**, use the `ZRANGE` **command** with the `WITHSCORES` **option**:

```
ZRANGE leaderboard 0 -1 WITHSCORES
```

This **command** returns all **elements** in the leaderboard set along with their **scores**. If you only want the **elements** without their **scores**, omit the `WITHSCORES` **parameter**.

To **retrieve** elements within a specific **score range**, use the `ZRANGEBYSCORE` **command**:

```
ZRANGEBYSCORE leaderboard 500 1500
```

This will **select** all **elements** with **scores** between `500` and `1500`.

Commands like `ZCOUNT` and `ZRANK` are useful for **counting** elements within a **score range** and finding the **rank** of a specific **element** in a **sorted set**:

```
ZCOUNT leaderboard 500 1500  # counts elements in the range
ZRANK leaderboard player1    # gets the rank of an element
```

What range should you use with the `ZRANGE` command to retrieve all elements in a Redis **sorted set**?

What happens if you add an element with an existing value to a sorted set?

This course will introduce you to the fundamentals of Redis and its use in real-world applications. We'll cover key Redis commands, data types, key expiration and transactions, as well as how to integrate Redis with Spring for efficient data caching.

This section provides an introduction to Redis, highlighting its core features and common use cases. You’ll learn how to install Redis on different platforms, including Windows and macOS, and get familiar with the basics of connecting to and starting the Redis server.

Here, we explore the essential Redis commands for managing and manipulating data effectively. You'll learn how to set, retrieve, increment, and delete data using commands like SET, GET, EXISTS, INCR, DECR, and tackle practical tasks to apply these concepts in real-world scenarios.

Here, you will learn about key Redis data types, including Lists, Sets, Sorted Sets, and Hashes. You will explore their functionality and practical applications through focused exercises designed to reinforce your understanding of each data type.

You'll explore advanced features of Redis, including managing key lifecycles, executing transactions, and leveraging the Pub/Sub messaging system. Additionally, you'll learn essential security practices to safeguard your Redis environment against unauthorized access.

This section introduces the fundamentals of caching and demonstrates how to configure Redis as a cache in a Spring application. It covers key caching annotations and practical examples of caching queries in web applications, concluding with a summary of the main concepts.

Introduction to Redis

Sorted Set

Key Commands

1. What range should you use with the `ZRANGE` command to retrieve all elements in a Redis sorted set?

2. What happens if you add an element with an existing value to a sorted set?

Introduction to Redis

Sorted Set

Key Commands

1. What range should you use with the ZRANGE command to retrieve all elements in a Redis sorted set?

2. What happens if you add an element with an existing value to a sorted set?

1. What range should you use with the `ZRANGE` command to retrieve all elements in a Redis sorted set?