AddMDBRecord

Public Class Form1
    Public mask As Integer

    Public Sub New()

        ' This call is required by the designer.
        InitializeComponent()

        ' Add any initialization after the InitializeComponent() call.
        ' set the Tag value for each textbox (this is the power of 2)
        ' it is the mask that is added/subtracted to a total (mask) if there text is text in the textbox or not
        txtRef.Tag = 1
        txtQty.Tag = 2
        txtYear.Tag = 4
        txtAuthor.Tag = 8
        txtPrice.Tag = 16
        txtBook.Tag = 32
        txtPub.Tag = 64
        'etc
        btnAddRecord.Enabled = False
        ClearTextBoxes(Me)
    End Sub

    Private Sub SaveRecord()

        Dim con As New OleDb.OleDbConnection
        Dim cmdinfo As New OleDb.OleDbCommand
        Dim dbProvider As String
        Dim dbSource As String

        dbProvider = "Provider=Microsoft.Jet.OLEDB.4.0; "
        dbSource = "Data Source = <path to your MDB ie C:\Users\Documents\Database2.mdb>;"

        con.ConnectionString = dbProvider & dbSource

        ' OK this is the wrong way to do it BUT it keeps it nice and simple for a demo
        ' really you should create this SQL statement dynamically in a different function and pass it into this function
        With cmdinfo
            .CommandType = CommandType.Text
            .CommandText = "SELECT * FROM MECHATRONICS"
            .CommandText = "INSERT INTO MECHATRONICS (`REFNO`, `QTY`, `BOOKTITLE`, `YEAR`, `AUTHOR`, `PRICE`, `PUBLISHER`) values (@REFNO,@QTY,@BOOKTITLE,@YEAR,@AUTHOR,@PRICE,@PUBLISHER)"

            .CommandType = CommandType.Text ' You missed this line
            .Parameters.AddWithValue("@xid", txtRef.Text)
            .Parameters.AddWithValue("@m_id", txtQty.Text)
            .Parameters.AddWithValue("@imodel", txtYear.Text)
            .Parameters.AddWithValue("@icolor", txtAuthor.Text)
            .Parameters.AddWithValue("@ch_id", txtPrice.Text)
            .Parameters.AddWithValue("@pt_num", txtBook.Text)
            .Parameters.AddWithValue("@icode", txtPub.Text)
        End With

        cmdinfo.Connection = con
        cmdinfo.Connection.Open()
        cmdinfo.ExecuteNonQuery()

        con.Close()

    End Sub

    Private Sub TextBox_TextChanged(sender As Object, e As EventArgs)

        ' OK this uses bit masking to validate that there is text in the textbox...
        ' it might seem like a lot of touble to go to but it works well.

        ' OK so what we are doing in the next few lines of code is 'Anding' the value of 'mask'
        ' with the tag value of the current textbox
        ' this will tell us if we have previously verified this textbox and confirmed that it contained text
        ' now, (because the user has modified the text in this textbox) we have to verify that it still contains
        ' some text, if not then we subtract the tag value from  mask, if it does then we leave the value of mask  alone…
        ' example
        'mask value of 20 and’ed with tag 4 = 4 (we have previously verified textbox 3)
        'mask value of 20 and’ed with tag 16 = 16 (we have previously verified textbox text 5)
        'mask value of 20 and’ed with tag 1 = 0 (we have NOT previously verified textbox text 1)

        If (mask And DirectCast(sender, System.Windows.Forms.TextBox).Tag) = DirectCast(sender, System.Windows.Forms.TextBox).Tag Then ' Mask already added
            If DirectCast(sender, System.Windows.Forms.TextBox).Text = String.Empty Then ' if there is no text in this textbox
                mask -= DirectCast(sender, System.Windows.Forms.TextBox).Tag ' subtract the mask
            End If
        ElseIf DirectCast(sender, System.Windows.Forms.TextBox).Text <> String.Empty Then ' mask is not added
            mask += DirectCast(sender, System.Windows.Forms.TextBox).Tag
        End If

        btnAddRecord.Enabled = mask = 127 ' for 6 textboxes set this value to 63 for 7 textboxes set it to 127 and so on

    End Sub

    Private Sub ClearTextBoxes(form1 As Form1)

        ' this function loops round all of the controls on this form and clears all the TextBoxes
        For Each ctrl As Control In Me.Controls
            If TypeOf ctrl Is TextBox Then
                CType(ctrl, TextBox).Text = "" ' set the initialy selected item to -1 (nothing)
                ' the next line is adding a delegate to each TextBox TextChanged event…
                ' it is basicly saying, when the text changes in the (any) textbox then fire TextBox_TextChanged event
                AddHandler CType(ctrl, TextBox).TextChanged, AddressOf Me.TextBox_TextChanged
            End If
        Next ctrl

    End Sub

    Private Sub btnAddRecord_Click(sender As Object, e As EventArgs) Handles btnAddRecord.Click
        ' this just calls the save record event, notice that this button is desabled UNTIL you have filled in every terxt box....even if you fill them in randomly or remove text....
        SaveRecord()
    End Sub

End Class