topic RE: Unique Items in a collection in Product Forum

Unique Items in a collection

OliverMohajeri — Thu, 13 Jun 2019 15:57:00 GMT

Does anyone have an existing activity or some VB code I can use to filter a collection to only include unique items?

Thank you 🙂

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Oliver Mohajeri
Consultant
EY
Europe/Zurich
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RE: Unique Items in a collection

lukasz.janiak — Fri, 14 Jun 2019 09:01:00 GMT

Hi, to get some unique values You can loop through the collection and for each value filter the collection to find values that occur only once, then just copy the value to the new collection with unique values.

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Łukasz Janiak
RPA Developer
Nordea
Europe/Łódź
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RE: Unique Items in a collection

david.l.morris — Fri, 14 Jun 2019 12:01:00 GMT

Hi Oliver,

I made an action in BP that does not use any custom code stage, but it's a bit convoluted because I have it accounting for any collection of any number of fields and gives the choice to deduplicate based on one or more fields. This kind of manipulation is likely better in code as you mentioned. But, to solve at least your use case, it's not very difficult to do in BP.
First, I'll assume you're trying to filter a collection for unique values in a single field. The most efficient way that I am aware of is to first use Sort Collection on the field you are focusing on. Then, use Loop stages to loop through the collection. Also, create two data items: Current Value and Previous Value.
Here's the flow or at least this is something like what you'd go for.: (Collection1 is your main collection and Collection2 is what you're copying unique values to)
Sort Collection1 on your field so that equal values are next to each other alphanumerically.
Loop Start
Get the current value of the field and store it in 'Current Value'
Decision stage: [Current Value]=[Previous Value]. (FYI: the first time through the loop it will compare the current value to empty text -- if this is a text datatype)
If Yes, Go to the Loop End
If No, add a new row to Collection2 and store the current row in Collection1 into the new row in Collection2
(still under If No) Also set the value in [Current Value] into [Previous Value]
Loop End

If you are trying to compare the entire row, there are a couple ways to do this. You can compare entire collections like [CollectionA]=[CollectionB] so you'd probably copy rows out into temporary, single row collections to compare them to each other. Otherwise, depending on the datatypes of your fields, you could compare a concatenation of all the fields, like [CollectionA.Field1] & [CollectionA.Field2] = [CollectionB.Field1] & [CollectionB.Field2].

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Dave Morris
3Ci @ Southern Company
Atlanta, GA
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RE: Unique Items in a collection

AmiBarrett — Fri, 14 Jun 2019 14:29:00 GMT

Here's some C# code I wrote to pull distincts. Should be easy enough to convert back to VB.

Inputs:
Collection - Collection
Column - Text

Outputs:
Sorted Collection - Collection

DataView dv = Collection.DefaultView;
Sorted_Collection = dv.ToTable(true, Column);

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Ami Barrett
Lead RPA Software Developer
Solai & Cameron
America/Chicago
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RE: Unique Items in a collection

OliverOng — Mon, 17 Jun 2019 21:05:00 GMT

Hi Oliver,

As previously mentioned, it's relatively trivial to create an object to loop through the input collection to retrieve unique values. I've included an action I created for this very purpose though I wouldn't suggest using this on large collections.

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Oliver Ong
Consultant
Ernst & Young LLP
America/Edmonton
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RE: Unique Items in a collection

John__Carter — Fri, 21 Jun 2019 10:33:00 GMT

To expand on Amy's suggestion, you can specify which columns you want as unique, like this.

Dim v As New DataView(Collection_In)
Collection_Out = v.ToTable(true, Column_Name_CSV.Split(","))

Note however that the output collection will only contain the columns you have specified, so this may not be exactly what you're after.

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John Carter
Professional Services
Blue Prism
Europe/London
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RE: Unique Items in a collection

kirtish.trivedi — Wed, 21 Oct 2020 14:04:00 GMT

Hi John,
This works well with VB but When I change the code to C# , I am getting compile error with the Split function. Can you please assist with the corresponding C# solution?

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Kirtish Trivedi
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RE: Unique Items in a collection

AmiBarrett — Wed, 21 Oct 2020 14:22:00 GMT

Try this:

DataView v = new DataView(Collection_In);
Collection_Out = v.ToTable(true, Column_Name_CSV.Split(','));

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Ami Barrett
Sr Product Consultant
Blue Prism
Plano, TX
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RE: Unique Items in a collection

NileshJadhavBP — Fri, 30 Oct 2020 15:05:00 GMT

Thanks for the code 🙂

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Nilesh Jadhav
Senior RPA Specialist
ADP
India
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