Select unique rows from the datatable and delete repeated rows with conditions

Hi team ,

In the attached excel
Join_table.xlsx (11.5 KB)

I want to delete the rows in which the line ids are repeating in the below pattern -

I want to pick the first row with line id = 1
Then it should pick row with line id = 2 but it should be the next to next row with line id =2
Then it should pick the row with line id = 3 but it should be the next to next row with line id = 3

and rest repeating rows should be deleted

So in the final table I should get values that are marked in yellow .

Please help me in this since this is very critical for our project.


Hi @gokul1904 write this code to get unique value


Hi @gokul1904 ,

Maybe we could create a Dictionary for this logic and then use it when Grouping the rows by LineID column for the Selection part.

Creation of Dictionary :

dictIndex = new Dictionary(Of String, Integer) from {{"1",0},{"2",1},{"3",2}}

Here, dictIndex is a variable of type Dictionary(Of String, Integer)

We could perform the Grouping of the rows based on LineID column and then select the row according to the dictionary corresponding values.

OutputDT = DT.AsEnumerable.GroupBy(Function(x)x("LineID").ToString).Select(Function(x)if(dictIndex.Keys.Contains(x(0)("LineID").ToString),x(dictIndex(x(0)("LineID").ToString)),x.First)).CopyToDatatable

Although there might be better approach for this, you could try and let us know if it works.

it looks like the case is still open

May we ask you to check the following requirement definition item:

  • it is supposed to take for 2: excel row 6 as it is the following 2 to the first occurrence (excel row 3)

But we don’t see the rules applied for the case 1
Excel row 2 vs. Excel row 5

so maybe a more clear rewriting the requirements with more specifics is needed. Also we would recommend to include the definition of handling the non duplicated ids