Prevent duplicates in list (virtual column type list)

[Sistemas_Ammade]

Hi! Is there a way to prevent duplicates in a virtual column type list? I would like to prevent duplicates just in the current order, (If I already picked apple, I should not add apple again?)
Thanks

[LeventK · Accepted solution]

I belive that Order Details column is a reverse-ref (isPartOf property of your Ref set to TRUE). If so;
you can set a valid_if expression in your child table for that [Fruit] column. Please make necessary changes in the expression to fit in your table schema.

COUNT(
    SELECT(
        Orders[Fruit],
        AND(
            [_THISROW].[Fruit] = [Fruit],
            [_THISROW].[RefColName] = [RefColName]
        )
    )
) = 0

[Sistemas_Ammade]

Thanks, I think it will be the solution, but I don’t know where my mistake is. If I understand, It will count Product (fruit) in Orders, but in my Orders table I don’t have a Product Column.

[Sistemas_Ammade]

Yeah, It works! thanks

[LeventK]

You’re welcome

[alex_gibson0111]

hi bro, can you share how to enter the formula? I have the same problem as you, but I’m still confused to solve it

[Steve]

This an old topic. Please start a new topic with a detailed explanation of your problem.

[alex_gibson0111]

hi steve, can you help me, I want to filter the order details to remove duplicates in the [menu id] column, can it be done?