Finding Duplicate rows in datatable in VB.net - vb.net

Question

I have a datatable in VB.net with few columns - Number, Name , Salary.
I want to get a list/table of "Number" that has the same ID and Salary Reapeted more than once.
for example:
Number: 1 , Name: Dan, Salary: 2000
Number: 2 , Name: Robert, Salary: 300
Number: 1 , Name: Shone, Salary: 2000
Number: 3 , Name: Kelvin, Salary: 2000
Number: 3 , Name: Arnon, Salary: 5000
For this table I will get back "1". because it has duplicate 1 with a salary of 2000.
Thanks for anyone help

Answer 1

I created the DataTable, then used Linq to group it by Number and salary. The Where clause only chooses groups with count greater than 1. The Select collects the Number field.
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
Dim dt As New DataTable
dt.Columns.Add("Number", GetType(Long))
dt.Columns.Add("Name", GetType(String))
dt.Columns.Add("Salary", GetType(Long))
dt.Rows.Add(1, "Dan", 2000)
dt.Rows.Add(2, "Robert", 300)
dt.Rows.Add(1, "Shone", 2000)
dt.Rows.Add(3, "Kelvin", 2000)
dt.Rows.Add(3, "Arnon", 5000)
Dim result = From row In dt
Group row By NumberSalary = New With {
Key .Number = row.Field(Of Long)("Number"),
Key .Salary = row.Field(Of Long)("Salary")}
Into Group
Where Group.Count > 1
Select New With {
Key .Number = NumberSalary.Number}
For Each r In result
Debug.Print(r.ToString) 'Prints { Number = 1 } in the Immediate window
Next
End Sub