How do you delete duplicate data in a string

Hello,

Below is the code I'm using to create the string of countries, is there a way to modify it to avoid duplicate countries? The problem is NSNs are sometimes duplicated which causes multiple countries to be included in the string.

Thanks.

Victor

  Dim ConnectionString As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=|DataDirectory|\aopt2002org.mdb;Persist Security Info=True;Jet OLEDB:Database Password=test"

        Dim objConnection As New OleDb.OleDbConnection(ConnectionString)
        objConnection.Open()

        'Dim da As New OleDb.OleDbDataAdapter("Select NIIN, code3 from IDENTIFICATION_DATA", objConnection)
        Dim da As New OleDb.OleDbDataAdapter("Select NSN, COUNTRYALL from AOP5", objConnection)

        Dim dt1 As New DataTable

        da.Fill(dt1)

        da.Dispose()
        da = Nothing

        'da = New OleDb.OleDbDataAdapter("Select NIIN, RN from REFERENCE_NUMBER_DATA", objConnection)
        da = New OleDb.OleDbDataAdapter("Select NSN, COUNTRY from AOP5A", objConnection)


        Dim dt2 As New DataTable

        da.Fill(dt2)

        Dim dv2 As DataView

        dv2 = dt2.DefaultView

        Dim cmd As OleDbCommand

        Dim SQLStr As String


        For Each dr As DataRow In dt1.Rows

            '.RowFilter = "NIIN='" & dr.Item("NIIN") & "'"
            dv2.RowFilter = "NSN='" & dr.Item("NSN") & "'"

            If dv2.Count > 0 Then


                SQLStr = "Update AOP5 Set COUNTRYALL='"

                For Each drv2 As DataRowView In dv2

                    SQLStr &= drv2.Item("COUNTRY") & ","
                Next
                'strip off trailing comma
                SQLStr = SQLStr.Substring(0, SQLStr.Length - 1)
                'add closing apostrophe
                SQLStr &= "'"
                'add WHERE clause
                SQLStr &= " Where NSN='" & dr.Item("NSN") & "'"
                ' MsgBox(SQLStr)
                cmd = New OleDbCommand(SQLStr, objConnection)
                'MsgBox(SQLStr)
                cmd.ExecuteNonQuery()
                cmd.Dispose()
                cmd = Nothing
            End If
        Next

You will not be able to do it in SQL.  You'll have to resort to VBA.

In VBA, get each row (or field) into a string, convert it to an array using the split function, sort the array (this will need to be written as a VBA function since there is no inbuilt sort), then select the unique values and do what you need to do with that ... either store them, or "join" them back into a string and put it back into the table, or print it, or whatever.

Ss

Thank you for the solution. Is there a way to sort the countries in the string? For example, in a row contains the following the data: BEL,USA,FRA,CAN.

Yes. Try this

Dim dTable As New DataTable
dTable.Columns.Add("Country", GetType(String))
For Each drv2 As DataRowView In dv2
    dTable.DefaultView.RowFilter = "Country='" & drv2.Item("Country")
    If dTable.DefaultView.Count = 0 Then
       Dim dRow as DataRow = dTable.NewRow()
       drow(0) = drv2.item("Country")
       dTable.Rows.Add(drow)
    End If
    dTable.DefaultView.RowFilter = ""
Next

For i As Integer = 0 to dTable.Rows.Count - 1
     SQLStr &= dTable.Rows(i).Item(0) & ","
Next

Thanks for the code. I included it at the end of the existing code but I received the following  error on the deign mode: "Variable SQLStr is used before it has been assigned a value" and when I run the project I received the folowing error: "The expression contains an invalid string constant: 'GRC." on line: dTable.DefaultView.RowFilter = "Country='" & drv2.Item("Country").

    Dim ConnectionString As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=|DataDirectory|\aopt2002org.mdb;Persist Security Info=True;Jet OLEDB:Database Password=testaopupdate"

        Dim objConnection As New OleDb.OleDbConnection(ConnectionString)
        objConnection.Open()

        'Dim da As New OleDb.OleDbDataAdapter("Select NIIN, code3 from IDENTIFICATION_DATA", objConnection)
        Dim da As New OleDb.OleDbDataAdapter("Select FIF, COUNTRYFUZEALLA from AOP5", objConnection)

        Dim dt1 As New DataTable

        da.Fill(dt1)

        da.Dispose()
        da = Nothing

        'da = New OleDb.OleDbDataAdapter("Select NIIN, RN from REFERENCE_NUMBER_DATA", objConnection)
        da = New OleDb.OleDbDataAdapter("Select FIF, COUNTRY from AOP5A", objConnection)


        Dim dt2 As New DataTable

        da.Fill(dt2)

        Dim dv2 As DataView

        dv2 = dt2.DefaultView

        Dim cmd As OleDbCommand

        Dim SQLStr As String


        For Each dr As DataRow In dt1.Rows

            '.RowFilter = "NIIN='" & dr.Item("NIIN") & "'"
            dv2.RowFilter = "FIF='" & dr.Item("FIF") & "'"

            If dv2.Count > 0 Then


                SQLStr = "Update AOP5 Set COUNTRYFUZEALLA='"

                ' For Each drv2 As DataRowView In dv2

                'SQLStr &= drv2.Item("COUNTRY") & ","
                'Next
                For Each drv2 As DataRowView In dv2
                    If SQLStr.Contains(drv2.Item("COUNTRY")) = False Then
                        SQLStr &= drv2.Item("COUNTRY") & ","
                    End If
                Next
                'strip off trailing comma
                SQLStr = SQLStr.Substring(0, SQLStr.Length - 1)
                'add closing apostrophe
                SQLStr &= "'"
                'add WHERE clause
                SQLStr &= " Where FIF='" & dr.Item("FIF") & "'"
                ' MsgBox(SQLStr)
                cmd = New OleDbCommand(SQLStr, objConnection)
                'MsgBox(SQLStr)
                cmd.ExecuteNonQuery()
                cmd.Dispose()
                cmd = Nothing
            End If
        Next
        Dim dTable As New DataTable
        dTable.Columns.Add("Country", GetType(String))
        For Each drv2 As DataRowView In dv2
            dTable.DefaultView.RowFilter = "Country='" & drv2.Item("Country")  **Error Line
            If dTable.DefaultView.Count = 0 Then
                Dim dRow As DataRow = dTable.NewRow()
                dRow(0) = drv2.Item("Country")
                dTable.Rows.Add(dRow)
            End If
            dTable.DefaultView.RowFilter = ""
        Next
        For i As Integer = 0 To dTable.Rows.Count - 1
            SQLStr &= dTable.Rows(i).Item(0) & "," ****Error line
        Next
        MsgBox("COMPLETED")

Change this

dTable.DefaultView.RowFilter = "Country='" & drv2.Item("Country").


to

dTable.DefaultView.RowFilter = "Country='" & drv2.Item("Country") & "'"


Also, the code I provide needs to replace this code

                For Each drv2 As DataRowView In dv2
                    If SQLStr.Contains(drv2.Item("COUNTRY")) = False Then
                        SQLStr &= drv2.Item("COUNTRY") & ","
                    End If
                Next

I replaced the code as shown below, but it still doesn't sort to countries.

For Each dr As DataRow In dt1.Rows

            '.RowFilter = "NIIN='" & dr.Item("NIIN") & "'"
            dv2.RowFilter = "FIF='" & dr.Item("FIF") & "'"

            If dv2.Count > 0 Then


                SQLStr = "Update AOP5 Set COUNTRYFUZEALLA='"

                ' For Each drv2 As DataRowView In dv2

                'SQLStr &= drv2.Item("COUNTRY") & ","
                'Next

                'For Each drv2 As DataRowView In dv2
                'If SQLStr.Contains(drv2.Item("COUNTRY")) = False Then
                'SQLStr &= drv2.Item("COUNTRY") & ","
                'End If
                'Next

                For Each drv2 As DataRowView In dv2
                    If SQLStr.Contains(drv2.Item("COUNTRY")) = False Then
                        SQLStr &= drv2.Item("COUNTRY") & ","
                    End If
                Next

                'strip off trailing comma
                SQLStr = SQLStr.Substring(0, SQLStr.Length - 1)
                'add closing apostrophe
                SQLStr &= "'"
                'add WHERE clause
                SQLStr &= " Where FIF='" & dr.Item("FIF") & "'"
                ' MsgBox(SQLStr)
                cmd = New OleDbCommand(SQLStr, objConnection)
                'MsgBox(SQLStr)
                cmd.ExecuteNonQuery()
                cmd.Dispose()
                cmd = Nothing
            End If
        Next
        Dim dTable As New DataTable
        dTable.Columns.Add("Country", GetType(String))
        For Each drv2 As DataRowView In dv2
            dTable.DefaultView.RowFilter = "Country='" & drv2.Item("Country") & "'"

            If dTable.DefaultView.Count = 0 Then
                Dim dRow As DataRow = dTable.NewRow()
                dRow(0) = drv2.Item("Country")
                dTable.Rows.Add(dRow)
            End If
            dTable.DefaultView.RowFilter = ""
        Next
        For i As Integer = 0 To dTable.Rows.Count - 1
            SQLStr &= dTable.Rows(i).Item(0) & "," '****Error line
        Next

Thanks.

Thank You.