Posted on

VB.net Check datatable for an existing account number

Hi group,

I'm attempting to write code to check to see if an existing account number exists. The user is to input a 10 digit account number. The code then is to query the database to see if that number exists. If it does, the message box displays the message that the number exists. However the code I've written isn't working as I wish. Can you offer some suggestions as to how to do this correctly?

Here's what I've attempted:

Private Sub tbxAccountNo_TextChanged(sender As Object, e As EventArgs) Handles tbxAccountNo.TextChanged
    If GlobalVariables.custpnl1 = 2 And tbxAccountNo.Text.Length = 10 And IsNumeric(tbxAccountNo.Text) = True Then
        Dim dt As New DataTable()
        Dim rowIndex As Integer = 0
        Dim searchID As Int64
        Dim strQ As String = String.Empty
        Dim conStr As String

        Dim msgAcctNo As String

        strQ = "SELECT CUST_ACCT_NO
                FROM CUSTREC 
                WHERE CUST_ACCT_NO = " & searchID
        conStr = "Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=C:\Users\Don\Documents\Visual Studio 2019\SalesForm\DWHRPT.mdf;Integrated Security=True"

        Dim dataAdapter As New SqlDataAdapter(strQ, conStr)
        dataAdapter.Fill(dt)
        dataAdapter.Dispose()

        For i As Integer = 0 To (dt.Rows.Count - 1)
            rowIndex = i
            If IsDBNull(dt.Rows(rowIndex)("CUST_ACCT_NO")) Then
                acctNoExists = False
            Else
                msgAcctNo = CStr(dt.Rows(rowIndex)("CUST_ACCT_NO"))
                acctNoExists = True
                MessageBox.Show("This account number exists.  Please enter a unique 10 digit account number.", "", MessageBoxButtons.OK)
                Exit Sub
            End If
        Next
    End If
End Sub

The "Text_Changed" event is used to fire this off - when there are 10 numeric characters in the textbox. That part seems to be working correctly as I've toggled it to stop at "For i As Integer = 0 To (dt.Rows.Count - 1)". But at this point, that's the only thing that seems to be working.

If you can teach me what I'm doing wrong, please feel free to do so.

As always, thanks for your help.

Don

Posted on

Why is the ListView box showing same headings twice?

Group,

I've written some code to populate a listview using 3 fields from a database. When creating the listview, I named the individual columns for appearance purposes, (Account No, Company Name and Name). Those columns are being populated appropriately as expected. However data column names are being shown in column 4 5 and 6, but with no data. What in my code is causing this? Any suggestions on how to fix this?

My code is as follows:

Private Sub tbxCompanyName_Leave(sender As Object, e As EventArgs) Handles tbxCompanyName.Leave
    lvwSearchCustomer.Visible = True
    Me.lvwSearchCustomer.View = View.Details
    Me.lvwSearchCustomer.GridLines = True
    Dim strQ As String = String.Empty
    Dim datasource As String = "Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=C:\Users\Don\Documents\Visual Studio 2019\SalesForm\DWHRPT.mdf;Integrated Security=True"
    conn = New SqlConnection(datasource)
    Dim searchID As String = tbxCompanyName.Text

    strQ = "SELECT CUST_ACCT_NO, 
            CUST_COMPANY_NAME,
            CONCAT(CUST_FIRST_NAME,' ',CUST_MIDDLE_INITIAL,' ',CUST_LAST_NAME) as MailingName    
            FROM CUSTREC 
            WHERE CUST_COMPANY_NAME LIKE '" & searchID & "%' OR CUST_LAST_NAME LIKE '" & searchID & "%'"

    cmd = New SqlCommand(strQ, conn)
    da = New SqlDataAdapter(cmd)
    ds = New DataSet
    da.Fill(ds, "Tables")
    Dim i As Integer = 0
    Dim j As Integer = 0
    ' adding the columns in ListView
    For i = 0 To ds.Tables(0).Columns.Count - 1
        Me.lvwSearchCustomer.Columns.Add(ds.Tables(0).Columns(i).ColumnName.ToString())
    Next
    'Now adding the Items in Listview
    For i = 0 To ds.Tables(0).Rows.Count - 1
        For j = 0 To ds.Tables(0).Columns.Count - 1
            itemcoll(j) = ds.Tables(0).Rows(i)(j).ToString()
        Next
        Dim lvi As New ListViewItem(itemcoll)
        Me.lvwSearchCustomer.Items.Add(lvi)
    Next

End Sub

In advance, thanks for your assistance.

Don