INVENTORY

[Admin11a1ab]

I’m working on an inventory app. I am using the formula below:
Sum(Select(Inventory[Amount], [ITEM ID]=[_THISROW].[Item ID]))
But the formula is summing the whole column [Amount] and not summing by [ID Item] on total stock available

the formula is summing the whole column [Amount] and not summing by [Item ID] on total stock available (IT MEANS THAT What I want is that if item id 01 has 5 products and 02 has 5 and 03 has 2, what each one has appears, not that they all add up)

[WillowMobileSys]

The expression in your screenshot is different than what you posted in the text.  It is using [_THISROW].[Name] not [_THISROW].[Item ID].  Does the Name column contain the correct value?  Just make sure Name and Item ID have the same EXACT value in the sheet.

[Admin11a1ab]

My fault, it is not Name it is Item ID

[WillowMobileSys]

As long as [_THISROW].[Item ID] has the same EXACT value as [Item ID] in your Inventory table then there shouldn't be any issue with the expression you have presented.  

If you are still having an issue, first check your data in the sheet and confirm the values for Item ID match exactly.  If looks good then please post an example from your app showing the row for which you are trying to calculate the "Total Stock Available" but it has the wrong value.

[Admin11a1ab]

Hello, I just uploaded a video of my current settings, and how it works in my app 

Video of my AppSheet settings