How should I store an array in a datastore?

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#1

Hey guys! So I was having a problem with Datastores in creating my loadout saving mechanic in my game, and it says I can’t use Arrays in Datastores. I’m not sure how I should go about putting the array into the datastore. Anyone have ideas? My code that I have is below in case you need to know what I’m doing

local DatastoreService = game:GetService("DataStoreService")
local Remote = game.ReplicatedStorage.Hotbar

local Hotbar = DatastoreService:GetDataStore("Hotbar")

Remote.OnServerEvent:Connect(function(p,a,b,c,d,e)
	Hotbar:SetAsync(p.UserId, {a,b,c,d,e})
end)
#2

You could just make it as a dictionary, every key is indexed using a number.

local dictionary = {
    1 = a,
    2 = b,
    3 = c
}
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#3

This is a pretty undescriptive error, it means that something in the array can’t be saved. What is a, b, c, d, and e?

#4

The error literally said arrays cannot be saved through data store service.

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#5

Okay so for context, I’m making a tower defense game and I’m trying to implement allowing you to customize what you start the game with (towers to play with) and each slot in the inventory has a value, (theres 5 slots) and they all have a value that simply just says the name of the tower.

example: a is = soldier, b is gladiator, etc…

#6

so like this?

local dictionary = {
	1 = a,
	2 = b,
	3 = c,
	4 = d,
	5 = e
}
#7

Yes, they can. Your script is literally the exact same thing as what he’s doing.

#8

If those soldier and gladiator are just instances, then it’s the problem.

#9

they are not, I put a stringvalue inside the slots to actually send the data over

#10

Yes, you can just use key as numbers to “act” as like an array.

#11

Then it’s the format issue of saving the data. In simple words, arrays cannot be saved through data store.

#12

I’m getting an error with the dictionary thing saying
image

edit: should I be sending the dictionary thru the event from the localscript?

#13

Then I’m really not sure, but the only idea I have left is just use a key to index an array of your troops.

local dataToSave = {
    Troops = {
        a,
        b,
        c,
        d
    },
    Money = …
}
#14

Okay, well thank you for the help!

#15

I changed the dictionary to use text values instead of numbers, and this works:

local dictionary = {
	slot1 = tostring(Slot1.Value),
	slot2 = tostring(Slot2.Value),
	slot3 = tostring(Slot3.Value),
	slot4 = tostring(Slot4.Value),
	slot5 = tostring(Slot5.Value)
}

I don’t know if the tostring was necessary

#16

I personally take the complicated method and HttpService:JSONEncode() everything that involves inventories, past player setting preferences, etc.

If I’m not incorrect, if you don’t use HttpService:JSONEncode() you’ll have issues storing Strings + Numbers in an array.

#17

This is incorrect.

JSON encryption is not a necessity for data storage. Not that it is useless, but you can store table types either way.

There is a misunderstanding of tables in this thread. Dictionaries are an extension of arrays. You can store a dictionary in a DataStore, and likewise you can store an array in a DataStore at less cost. Our games do it consistently with no external modules.

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OP, I’m not sure why that error is throwing, but I would suspect it is the data types that you are attempting to save.

#18

Oh, I’ve experienced an issue in the past where my code printed an error although I was able to do it before, where it said “Cannot store Dictionary in DataStore” and my old and newer script were relatively the same, utilizing only numbers + strings. No instances because you cannot save those to a DataStore.

The minute I switched over to HttpService:JSONEncode() the error immediately went away so I assumed it was the mix of numbers and such.

Thanks for the elaboration though.

#19

I’m not an expert at anything under the hood of Luau. You will see certain improvements from encryption likely because I imagine less bytes are needed.

Ages ago I would write my Data with encryption, now my primary use-cases for JSON involve actual Http requests.

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