Delete (Remove) duplicate rows from DataTable in C# and VB.Net

Hi mahjoubi,

Refer below code.

C#

DataTable dt = new DataTable();
dt.Columns.Add("Item");
dt.Columns.Add("Qty");
dt.Columns.Add("Price");
dt.Rows.Add("a", 1, 10);
dt.Rows.Add("b", 2, 20);
dt.Rows.Add("c", 3, 30);
dt.Rows.Add("", 3, 0);
dt.Rows.Add("", 4, 0);
dt.Rows.Add("a", 4, 0);

List<string> duplicates = (from dr in dt.AsEnumerable()
                            group dr by dr["Qty"] into groups
                            where groups.Count() > 1
                            select groups.Key.ToString()).ToList();

for (int i = dt.Rows.Count - 1; i >= 0; i--)
{
    if (string.IsNullOrEmpty(dt.Rows[i][0].ToString()))
    {
        if (duplicates.Contains(dt.Rows[i][1].ToString()))
        {
            dt.Rows[i].Delete();
        }
    }
}

VB.Net

Dim dt As DataTable = New DataTable()
dt.Columns.Add("Item")
dt.Columns.Add("Qty")
dt.Columns.Add("Price")
dt.Rows.Add("a", 1, 10)
dt.Rows.Add("b", 2, 20)
dt.Rows.Add("c", 3, 30)
dt.Rows.Add("", 3, 0)
dt.Rows.Add("", 4, 0)
dt.Rows.Add("a", 4, 0)

Dim duplicates = (From dr In dt
                    Group dr By Qty = dr("Qty") Into Group, Count
                    Where Count > 1
                    Select New With {Key Qty}.Qty).ToList()

For i As Integer = dt.Rows.Count - 1 To 0 Step -1
    If String.IsNullOrEmpty(dt.Rows(i)(0).ToString()) Then
        If duplicates.Contains(dt.Rows(i)(1).ToString()) Then
            dt.Rows(i).Delete()
        End If
    End If
Next

Output