Why would UpdateIf add a new blank record to a collection sometimes?

[sfasweqq]

I have a collection of records, and a collection of selected records from that first collection.

My intent is to have a form that will update all the selected records in the first collection with the values from the form, depending on if a value was entered into the form or not.

This works with textboxes but when I try to update one of the fields (a multi-select choice field, so a table of "Value") I get two different problems:

• Around 1 in every 5 times it will instead create a new blank record in the collection holding only that one multiple choice field
• Another 1/5 chance of nothing happening at all

The code that works 3/5 times and breaks in two different ways is something like this:

With({ newItems: cmbNewAddItem.SelectedItems },
    UpdateIf(colPurchaseItems, Index in colSelections.Index, {
        Quantity: Coalesce(Value(txtNewEditQuantity.Text), Quantity),
        ActualPrice: Coalesce(Value(txtNewEditPrice.Text), ActualPrice),
        GL: Coalesce(Value(txtNewEditGL.Text), GL),
        Items: If(CountRows(newItems) > 0,
            newItems,
            Items
        )
    })
)

[RandyHayes]

@sfasweqq 

Your problem is that you have a syntax issue with the UpdateIf.

The second parameter of the UpdateIf is the criteria that is used to match a record.

Your criteria is Index in colSelections.Index.  So this will evaluate to true if the Index is in that collection and false if not.  That will NOT match the record.  

You need to specific actual criteria for that record.

I am not able to provide too much more information as these see to be some made up collections that have a variety of purposes. 

If the above doesn't give you a clue as to what to change, then if you can expand on the purposes and meanings of the Index and the other collection perhaps that would assist.

I hope this is helpful for you.

[sfasweqq]

Hi, I'm a little confused.

Doesn't

colPurchaseItems, Index in colSelections.Index

 match true if the item in colPurchaseItems has an Index column that is in colSelections.Index, so it will only update those items?

[RandyHayes]

@sfasweqq 

Yes and no - 

Yes it will be true if Index is in colSelections.Index.

No it will not necessarily just update those items.  However, they would if Index is as column in the collection - but, it's only going to do it once.  

AND, looking at it from the perspective of Index and an Index collection, then I would say you are better off working from that collection as the source rather than the other.

My other question would be - is Index the primary key of the data?  Or, is this in a SharePoint list datasource that you are originating from?

[sfasweqq]

Thanks for helping, it actually ended up being a dumb mistake on my part and nothing to do with the code I shared. I had another combo box with a Default and OnChange update that was firing after that code and either cancelling the change or inserting blank rows based on how fast things happened I guess.

Sorry for wasting your time!

[RandyHayes]

@sfasweqq 

No problem!  Always good to avoid On... actions that perform actual logic like that.  They will bite you in the end and it's not really the "PowerApps way".

Glad you found it!!

[Runner55552]

I am having the exact same issue. I have a button that uploads data from a Collection to a Dataverse data table using UpdateIf.  I loop through all the records in the Collection using ForAll. Occasionally, even when there is a single record in the Collection, instead of updating my matching value from the Dataverse table, it adds 2 new blank records instead.  Code is here: 
//Loops through the collection and then updates Dataverse table only with items/rows in the collection, clears collection
ForAll(
PieceAddInfo,
UpdateIf(
TaraconYards,
PieceUID = PieceUID_Col,
{
Location: Location_Col,
PieceStatus: PieceStatus_Col,
PieceNote: PieceNote_Col,
TrailerNumber: TrailerNumber_Col

}
)
);
Clear(PieceAddInfo)