datagrid validation for duplicate values

[vammy]

Hi Guys,

I need Some help in validating a particular coloumn in datagrid for duplicate values before inserting into database.Im using datatable.
Please help with some example code.appreciate our help.
regards,
vamsee

[bhagawatshinde]

Use this.

Dim duplicates = dt.AsEnumerable().GroupBy(Function(i) i.Field(Of String)("Col1")).Where(Function(g) g.Count() > 1).Select(Function(g) g.Key)

        For Each ed In duplicates
            Console.WriteLine(ed)
        Next

Hope it will help you. or
if u want to manipulate or process datatable for duplicate rows you can follow as same code

int[] listOfItems = new[] { 4, 2, 3, 1, 6, 4, 3 };
var duplicates = listOfItems
    .GroupBy(i => i)
    .Where(g => g.Count() > 1)
    .Select(g => g.Key);
foreach (var d in duplicates)
    Console.WriteLine(d);

[vammy]

Hi,
Thanks for ur reply.,
Where shld i put the above code?Whn im trying to put this in cellvalidated function,im getting a run time exception.please let me know.thanks.

[vammy]

and also it shld display an error message like "duplicate value inserted".,
thanks very much for ur help.

[vammy]

Hi Bhagvat,
Need you help here please..,where to put the above codes?i have tried placing it in validation sub,but getting an error,,
my requirement is simple:
I have a plot column in my datagrid.,users wil be entering plot numbers,whn ever they enter a plot no which they have already entered an error shld be displayed to them..
please help,thanks

[bhagawatshinde]

Hi vammy,
You require the repetation on keypress on cell or simple way to write for loop code on button to check cell repetation values.

[vammy]

Hi Bhagvat,
How do i do that?Im new to vb.net.Could u please assist me with some code?thanks..

[bhagawatshinde]

take button name 'Check Repetition' on click event write the following code

For k = 0 To dtgtest.RowCount - 1
                Dim str As String = dtgtest.Item(0, k).Value
                Dim str1 As String = dtgtest.Item(0, k + 1).Value
                If str = str1 Then
                    MessageBox.Show("Repeat value Found in row " & k + 1)
                End If
            Next

this code is not tested it will work hope so if no then cooming with solution wait

[bhagawatshinde]

Try this

Try
            Dim arr As New ArrayList
            For k = 0 To dtgtest.RowCount - 1
                If Not arr.Contains(dtgtest.Item(0, k).Value) Then
                    arr.Add(dtgtest.Item(0, k).Value)
                Else
                    MessageBox.Show("Repetation found in row " & k + 1)
                End If
            Next
        Catch ex As Exception
            MessageBox.Show(ex.Message)
        End Try

[vammy]

thts fantastic brother..!:)
got exactly what i wanted..,thank you so much..god bless..