Mismatch between Lookup Function and Gallery Item

[BLuca]

Hello everyone,
I'm building an app where I scan for a QR code and then update some values on a Sharepoint List.

Most of the items I'm scanning have a Serial Code, so they are unique values.
Some items don't have a serial number (their serial value is set to "no serial"), so I decided to create an "item pool" (there will be many items of the same kind), by creating a new coulmn on the list, named "Quantity", which must increase or decrease by 1 depending on which kind of scan I do (take or return).
I also created a Gallery in which every item is listed so I could eventually compare with it.

Here's the issue: once the item has been found, I can pretty much update every column right (so that I know that I found the right item), the Quantity value is updated with the next item on the list, instead of the same row value.
For example: The item I'm scanning has quantity 4 and the next item on the list has quantity 2. If I scan for the Item to be taken, I'm getting the updated value of Quantity to 1 (next item quantity-1) instead of getting 3(my item quantity-1) (and it does the same with the return operation).
All of this operations are inside the same Patch function so it doesn't make sense to me why the other values are updated correctly but not this one.

Is this some kind of bug or am I missing something?

I hope my explanation of the issue is understandable.
Please help, thank you!!

P.S.: I could also upload screenshots of the code, I will do it soon.

[BLuca]

Helo @BCBuizer 
Yes, that's the case. I have 2 buttons to make 2 different scan actions: one that takes an item (sets the item as "in use") and the other one to return the item (sets the item as "Available").
So, are you saying that "ForAll" function is not necessary to scan every item on the sharepoint list? Just Patch function, together with Lookup function will just search in the whole list?
Still I'm not understanding why every other value is correctly selected and updated for the same record except for Quantity value..
Anyways, I'm going to try now, so I'll update you soon.

Thank you.

[BCBuizer]

Hi @BLuca ,

In the trace I found you have 4 items. What the formula with the ForAll loop did:

1. Patch the selected item (2nd one in the table) with the Quantity -1 value of the 1st item in the list: 0

2. Patch the selected item (2nd one in the table) with the Quantity -1 value of the 2nd item in the list: 5

3. Patch the selected item (2nd one in the table) with the Quantity -1 value of the 3rd item in the list: 3

4. Patch the selected item (2nd one in the table) with the Quantity -1 value of the 4th item in the list: 6

By removing the ForAll loop, only the Patch/LookUp for the 2nd item remains, which is the one you need:

1. Patch the selected item (2nd one in the table) with the Quantity -1 value of the 1st item in the list: 0

2. Patch the selected item (2nd one in the table) with the Quantity -1 value of the 2nd item in the list: 5

3. Patch the selected item (2nd one in the table) with the Quantity -1 value of the 3rd item in the list: 3

4. Patch the selected item (2nd one in the table) with the Quantity -1 value of the 4th item in the list: 6

[BLuca]

Hi @BCBuizer Ok that makes sense to me.
The issue now is that Quantity is not recognized anymore, and also 'Current owner'.
Screenshot attached (errors are the same).

[BCBuizer]

Hi @BLuca ,

In the trace I found different column names: "UnitNr" for Quantity and "Whotookit" for 'Current Owner' although those may be the internal names:

Patch(
	DemoItemLaboratorio;
	LookUp(
		DemoItemLaboratorio;
		(('Serial number' = Seriale) //Seriale variable is set OnScan (in this case will find "no serial")
		&& (Title = Oggetto) //Also set OnScan
		&& (Office.Value = Ufficio)) //Also set OnScan
	);
	{
		Customer: CustomerName.Text; //Ok
		'Previous Owner': If(IsBlank(Text(CurrentOwnerList2));Text('Previous Owner');Text(CurrentOwnerList2)); //Ok
		Whotookit: Text(User); //Ok
		UnitNr: UnitNr-1; //Changed this due to removal of the ForAll loop
		'Serial?': false; //Ok
		'Request date': (Today()); //Ok
		Status: If(Quantity = 0;{Value: "In use"};{Value: "Available"}); //not even tested this one, it will come later
		'Due date': (Today() + 15) //Ok
	}
);

If this doesn't work, check the DisplayName of the column in the datasource.

[BLuca]

Hi @BCBuizer yes I saw them too.
They were the old names I gave to the columns.
I'm having issues with Sharepoint List lately. It doesn't save the columns settings often. The current names are Quantity and Current Owner.

Also, if I try to type 'Unit Nr' instead of 'Quantity', it says that the column does not exist.
Any suggesions? Do I delete the connection to the list and connect it again? Do I have to re-create the Sharepoint List perhaps?

Thank you.

[BCBuizer]

Hi @BLuca ,

Try using Intellisense when editing the formula to see what suggestions you are given and try some of the options that look right.

[BLuca]

Hi @BCBuizer 
yes I have already tried but neither 'Current Owner' or 'Quantity' are suggested once I remove Forall function.
If Forall function is there, then there is no issue finding those columns.

Thank you.

[BLuca · Accepted solution]

I managed to solve my issue!
All I had to do was to filter my gallery of items in a different way:
by filtering the only one item found on the Sharepoint List (filtered by 3 conditions), I could take all the filtered data directly from my gallery (quantity and all the rest of the data that was already working fine).

Thank you @BCBuizer for your support.