Question

I’ve been trying to use an IF/ELSE statement to query my MySQL database, but can’t seem to figure out why the ELSE statement is being ignored by VB. Here’s the code – any help would be appreciated:

dbConn = New MySqlConnection("Server=" & FormLogin.ComboBoxServerIP.SelectedItem & ";Port=3306;Uid=qwertyuiop;Password=lkjhgfdsa;Database=zxcvbnm")
    Dim account As Boolean = True
    If dbConn.State = ConnectionState.Open Then
        dbConn.Close()
    End If
    dbConn.Open()
    Dim dbQuery As String = "SELECT * FROM customer WHERE accountNumber = '" & TextBoxSearch.Text & "';"
    Dim dbData As MySqlDataReader
    Dim dbAdapter As New MySqlDataAdapter
    Dim dbCmd As New MySqlCommand
    dbCmd.CommandText = dbQuery
    dbCmd.Connection = dbConn
    dbAdapter.SelectCommand = dbCmd
    dbData = dbCmd.ExecuteReader
    While dbData.Read()
        If dbData.HasRows() = True Then
            MessageBox.Show("Customer Account Found!")
        Else
            MessageBox.Show("No Customer Records Found!  Please try again!")
            dbData.Close()
        End If
    End While

My intent is to replace the messagebox in the “IF” clause with the code that will populate my form with the data from the database.

Answer 1

That’s because you are already reading it:

While dbData.Read()
  If dbData.HasRows() = True Then
    MessageBox.Show("Customer Account Found!")
  Else
    MessageBox.Show("No Customer Records Found!  Please try again!")
    dbData.Close()
  End If
End While

If your reader has no records, the whole While loop will be skipped.

Try it the other way around:

If dbData.HasRows Then
  While dbData.Read()
    'looping through records here
  End While
Else
  MessageBox.Show("No Customer Records Found!  Please try again!")
End If

And also the obligatory note: Don’t keep your connections open and alive. Use the Using End Using bracket to automatically close your disposable objects.