KeyValueStore

The KeyValueStore singleton class is a server-side key-value storage utility with persistence, meaning that the values are kept between server executions in the database.

In this example, every time a player sends a message we store it using KeyValueStore:Set. To retrieve the value once it has been stored, we use KeyValueStore:Get and supply a function that will be called with the value

Events:Subscribe("PlayerChat", function(args)
    KeyValueStore:Set("MostRecentChatMessage", args.text)
    KeyValueStore:Get("MostRecentChatMessage", function(value)
        print("The most recent chat message is:", value)
    end)
end)

Notes:

1. If a key does not exist, then KeyValueStore:Get will return nil
2. Although internally we are interacting asynchronously with a database to implement the storage for this utility, caching is used so that all changes have the appearance of immediately taking effect. Caching is done whenever possible & multiple outstanding :Get requests for the same key are aggregated into one call to the database. In other words, the database usage is highly optimized and minimized.