Set and Sorted Set
Explore the functionality of Redis set and sorted set data types using Go. Learn to add, retrieve, check membership, count, remove items, and perform unions on sets. Understand sorted sets with unique elements, scores, ranking, incrementing scores, and range queries to build ordered and efficient applications.
Set
A Redis set data type is similar to a set data structure that you may have used in programming languages such as Java. The two most important characteristics of a set in Redis are:
They contain unique strings only. In other words, duplicate elements are not allowed.
There are no ordering guarantees. When we retrieve items from a set, they may not be in the same order as when we added them to the set.
Just like the string data type, a set in Redis seems simple, but it includes a rich set of features. Let’s explore a few of them in the following sections.
The SAdd method
To do anything useful with a set, we first need to add items to it. We can do that with the SAdd method. In the example below, we add three fruits (apple, orange, and banana) to a set called fruits:
client.SAdd(ctx, "fruits", "apple", "orange", "banana")
The SMembers method
To get all the members of a set, we can simply use the SMembers method. Here, we get all the fruit names from the fruits set. This returns a string slice that we can iterate over:
fruits := client.SMembers(ctx, "fruits").Val()
The SIsMember method
If we want to check whether a specific exists in the set, we can use the SIsMember method. In the example below, we ...