UpdateAsync returning nil

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#1

Hi, I am trying to make a script where it saves the game when you leave. I don’t know why, but UpdateAsync always returns nil. Does anyone know how to fix this? Thanks.

game.Players.PlayerRemoving:Connect(function(player)--PlayerRemoving is when a player leaves.
	local playerUserId = player.UserId
	
	
	local updata = {}
	
	for i, v in ipairs(player.Upgrades:GetChildren()) do
		updata[v.Name] = v.Value
	end

	
	
	
	local success, errormessage = pcall(function()
		upgradeData:UpdateAsync(playerUserId, function(oldData)
			local previousData = oldData or {DataId = 0}
			if updata.DataId == previousData.DataId then
				print("then")
			else
				return nil --It always returns nil
			end
		end)
	end)
	
	
	
end)
#2

You’re checking for updata.DataId inside of a table where the property doesn’t exist. Therefore, the if condition will always return nil

P.S.

You should print any potential error messages

if not success then
    warn(errormessage)
end
#3

Oh, thanks!

I don’t know how, but it worked on another data store I was doing. Can you explain why it works on this one?

Script:

game.Players.PlayerRemoving:Connect(function(player)--PlayerRemoving is when a player leaves.
	local playerUserId = player.UserId
	
	
	local data = {
		Cash = player.leaderstats.Cash.Value;
		Rebirths = player.leaderstats.Rebirths.Value;
	}
	
	for i, v in ipairs(player.CodeStats:GetChildren()) do
		data[v.Name] = v.Value
	end

	
	
	local success, errormessage = pcall(function()
		myDataStore:UpdateAsync(playerUserId, function(oldData)
			local previousData = oldData or {DataId = 0}
			if data.DataId == previousData.DataId then
				return data
			else
				return nil
			end
			
		end)
	end)
	
end)
#4

I tried doing

if updata.Data == previousData then

and it didn’t work

#5

Not .Data sorry, just ignore that

if updata == previousData then
#6

The reason why it works there is because you have an IntValue (I assume) named DataId that’s inserted into the table at runtime during the loop, and the value of the IntValue matches either the previous value or the default value of DataId in the function.

Also, if you have two callback functions modifying the player’s data, if one of the them returns nil then the player’s data will likely be erased

#7

So you’re saying there is something in the data table named DataId? I don’t understand. Can you make a more visual explanation if possible?

#8

I’m saying the loop:

for i, v in ipairs(player.CodeStats:GetChildren()) do
		data[v.Name] = v.Value
	end

is adding values to the data table and one of those values is like an IntValue named DataId that’s being inserted as well. I, of course, don’t have confirmation of this because I don’t know how your game is structured.

At the end of your loop, the table will have a new key named DataId that you’re checking later on:

if data.DataId == previousData.DataId then
	return data
else
	return nil
end

This is likely why your second script works but the first one doesn’t. Either the first one doesn’t have a key called DataId or the value of DataId is likely a different number

#9

But what about this part? Why does this part save?

local data = {
		Cash = player.leaderstats.Cash.Value;
		Rebirths = player.leaderstats.Rebirths.Value;
	}
#10

It’s attached to the same table

#11

Hm. So then how do I fix it???