Working with Duplicates DataTables

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1

Hi everyone,

I have created a datatable with col. (FileName [String], NewFileName [String], IsDuplicate [Boolean]).
I want to iterate through the DtTbl to find duplicate values in NewFileName. Each a duplicate NewFileName is found I want to set the Col. IsDuplicate to True for all rows which has the duplicated NewFileName.

I am at a loss of how I can achieve this, I appreciate any help that you can give.

Many thanks

2

@SamLong,

Here, do you want to compare filename and newFileName columns to find duplicates ?

3

Just the NewFileName column as the FileName column should already be unique

4

With a dataview object you can select automically only the unique rows.

You see this in an onder post How to read next column - #2 by tdhaene

5

Group rows by NewFileName, then for groups with more than 1 element set flag to true.
Something like this (can’t check syntax but should get you on track):

Foreach row in yourDT.AsEnumerable().GroupBy(Function(dr) dr.Field(Of String)("NewFileName")).Where(Function(grp) grp.Count > 1).Select(Function(grp) grp.Value)

row.Field(Of Boolean)("IsDuplicate") = True
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