Access 2010 - VBA - Editing underlying table data using text boxes on a form - vba

Question

I'm using too many boolean indicators and I'm sure its very inefficient/stupid...
Currently in the Access database I have numerous forms which are used to edit underlying records. Text boxes on these forms are not bound to the underlying table. I do not wish to bind the form or any of its controls directly to the underlying tables, if the data is editable by the user (less human error from users). Instead I've a Boolean for every control which contains editable information.
Users enter 'edit mode', change information (Boolean now equals true), click 'save changes', review the changes and accept and then the relevant queries are run to reflect these changes. I like this order of events however, I'm creating increasingly complex forms with 40 or so editable controls and hence 40 Boolean variables.
Anyone think of an nicer alternative? Is there a property of the controls (mainly text boxes) I can use?
CODE:
Private Sub CommentsText_AfterUpdate()
If Nz(Me.CommentsText) = "" Then
CommentsEdit = False
Else
CommentsEdit = True
End If
End Sub
'Within the 'save changes' method
If CommentsEdit Then
CommentsEdit = False
sql = "Update [General-CN] Set [Comments] = '" & Left(Me.CommentsText, 250) & "' Where [ID ( G )] = " & Me.[GeneralPK] & ";"
DoCmd.RunSQL (sql)
End If

Answer 1

normally data validation during data entry is one the things that normally, in my experience, before or later put the developer on his knees.
From your question, I can feel that the core is to preserve database integrity. Unfortunately there is no way to ABSOLUTELY preserve your database. If you give access to it to users you can only use some tips:
1 - If possible use combo-box with defined entries instead of using textboxes in which user is free to digit anything (e.g. think an expert system that collect data about the same problem written in many different ways!!!)
2 - Check data integrity and coherence (e.g. type) before writing it to database
3 - When the data is just a boolean (flag) you can use switches, radio button or checkboxes.
These tips help in developing a user interface more friendly and faster from the point of view of data entry.
After this I can give you another way to validate your data.
If you want to show data to user before saving you can create the mask in which you enter your data with unbounded textboxes.
Then, when he clicks the Save Button, you can show a 2nd form, opened in append mode, in which you show data with textboxes bounded to your db.
If he accepts the data, you can save otherwise you can cancel the data entry preserving your database. I post you here some lines of code with an example taken from an application of mine. It's the part in which I manage contacts
The form allows to input contact data
'------------------------------------------------------
' Temp variables to store entries before saving /cancelling
'------------------------------------------------------
Dim bolValidationErr As Boolean
Dim m_vntLastName As Variant
Dim m_vntFirstName As Variant
Dim m_vntFC As Variant
Dim m_vntVATNum As Variant
Dim m_vntAddress As Variant
Dim m_vntCity As Variant
Dim m_vntZIP As Variant
Dim m_vntCountry As Variant
Dim m_vntPhone As Variant
Dim m_vntFAX As Variant
Dim m_vntEMail As Variant
Dim m_vntNote As Variant
Dim m_vntContactType As Variant
'------------------------------------------------------
' Suppress error "Impossible to save the record...
'------------------------------------------------------
Private Sub Form_Error(DataErr As Integer, Response As Integer)
If DataErr = 2169 Then
Response = True
End If
End Sub
'------------------------------------------------------
' W/o customer last name, cancel saving
'------------------------------------------------------
Private Sub Form_Beforeupdate(Cancel As Integer)
On Error GoTo Err_Form_BeforeUpdate
Dim strType As String
Dim bolNewContact As Boolean
Dim intErrFC As Integer
Dim intErrVATNum As Integer
Dim intErrFullName As Integer
Dim strErrMsg As String
Dim intAnswer As Integer
bolValidationErr = False
'------------------------------------------------------
' If LastName is missing, cancel data saving
' Cancel = True cause the raise of the error
' "You can't save record at this time..."
' SetWarnings doesn't work. It's needed to intercept with Form_Error event
'------------------------------------------------------
If HasNoValue(Me.txtLastName) Then
strErrMsg = "Put here your error msg"
intAnswer = MsgBox(strErrMsg, vbOKOnly + vbExclamation, "Entry Error")
Cancel = True ' Cancel db update
Call BackupCurrentData ' Store data input until now
bolValidationErr = True ' Unvalid data
Exit Sub
End If
Exit_Form_BeforeUpdate:
Exit Sub
Err_Form_BeforeUpdate:
GoTo Exit_Form_BeforeUpdate
End Sub
'------------------------------------------------------
' Store the content of textboxes for restoring them in case
' of cancelling
'------------------------------------------------------
' If the record is new, if the BeforeUpdate event is cancelled,
' NULL values are restored (in fact there were no data!!!)
'------------------------------------------------------
Private Sub BackupCurrentData()
m_vntLastName = Me.txtLastName
m_vntFirstName = Me.txtFirstName
m_vntFC = Me.txtFC
m_vntVATNum = Me.txtVATNum
m_vntAddress = Me.txtAddress
m_vntCity = Me.txtCity
m_vntZIP = Me.txtZIP
m_vntCountry = Me.txtCountry
m_vntPhone = Me.txtTelNum
m_vntFAX = Me.txtFax
m_vntEMail = Me.txtEmail
m_vntNote = Me.txtNotes
m_vntContactType = Me.cmbContactType
End Sub
'------------------------------------------------------
' Restore contents of textboxes before cancelling operation
'------------------------------------------------------
Private Sub RestoreCurrentData()
Me.txtLastName = m_vntLastName
Me.txtFirstName = m_vntFirstName
Me.txtFC = m_vntFC
Me.txtVATNum = m_vntVATNum
Me.txtAddress = m_vntAddress
Me.txtCity = m_vntCity
Me.txtZIP = m_vntZIP
Me.txtCountry = m_vntCountry
Me.txtTelNum = m_vntPhone
Me.txtFax = m_vntFAX
Me.txtEmail = m_vntEMail
Me.txtNotes = m_vntNote
Me.cmbContactType = m_vntContactType
End Sub
I think that this code can be adapted to your needs.
The variable names are enough self-describing
Anyway feel free to contact me if you need further help.
Bye,
Wiz:-)