Duplicate check in Collection

[LordsBH]

Hello all,

I'm trying to make a barcode input check for duplicates before writing to a collection with the following formula:

If(
    BarcodeScanner1_1.Text exactin ConsigmentTable.Serial_Number,
    UpdateContext({MessageBoard: "Duplicate Serial, please check"}),
    Collect(
        ConsigmentTable,
        {
            Serial_Number: BarcodeScanner1_1.Value,
            Checkedby: User().FullName,
            Scan_Date: Today(),
            Quantity: 1
        }
    )
)

However it seems to always go straight to the FALSE part of the statement. 

Also did try with:

If(LookUp(ConsigmentTable, BarcodeScanner1_1.Text in Serial_Number, "OK") <> "OK", ...

But alas, same thing. If anyone has a suggestion, I'll greatly appreciate the input!

I did try the suggestion listed here:
 https://powerusers.microsoft.com/t5/General-Discussion/Prevent-duplicate-values-in-a-collection-data...

[v-monli-msft · Accepted solution]

Hi @LordsBH ,

In your Lookup formula, may I ask what is this "OK" referring to? Is it one of the column's column name of ConsigmentTable?

Try to use below formula instead:

If(!IsBlank(LookUp(ConsigmentTable, BarcodeScanner1_1.Text=Serial_Number)) , ...

Regards,

Mona

[LordsBH]

It worked like a charm, @v-monli-msft, thanks!

I had to change the BarcodeScanner1_1.Text to BarcodeScanner1_1.Value, but it did work