Make all fields mandatory to be filled in - ms-access

Question

This question is continued from here: Add user input to Excel table upon upload to Access database
Now that I have my fields connected to a table in my database, I want to make sure that everyone fills them in. Upon clicking the Import button, I want to check the fields (SANumber, SerialNumber, CustomerName, and LyoSize) to make sure it will be a 'valid upload'.
I have this code so far:
Function CheckInputs() As Boolean
If Me.SANumber.value Or Me.SerialNumber.value Or Me.CustomerName.value Or Me.LyoSize.value = Null Then
CheckInputs = True
Else
CheckInputs = False
End If
End Function
'Import MCL Files Code
Private Sub ImportMCL_Click()
On Error GoTo ErrorHandler
'disable ms access warnings
DoCmd.SetWarnings False
Call CheckInputs
If CheckInputs = True Then
MsgBox "All inputs must be entered!"
Exit Sub
Else
'load spreadsheet in .xls format
DoCmd.TransferSpreadsheet acImport, 8, "_MCL_UPLOAD", selectFile(), True
DoCmd.OpenQuery "UpdateMCL"
Call InsertInto_MASTER_UPLOAD
Call Delete_MCL_UPLOAD
MsgBox "MCL Imported Successfully!"
're-enable ms access warnings
DoCmd.SetWarnings True
End If
Exit Sub
ErrorHandler:
MsgBox "There was an Error: " & Err & ": " & Error(Err)
End Sub
It should work, but keeps on giving me the
ERROR: 13. Type Mismatch

Answer 1

You need to specifically check each field for null - you cannot do it this way:
If Me.SANumber.value Or Me.SerialNumber.value Or _
Me.CustomerName.value Or Me.LyoSize.value = Null Then
Something like
If IsNull(Me.SANumber) Or IsNull(SerialNumber) Or _
IsNull(Me.CustomerName) Or IsNull(Me.LyoSize) = Null Then
You should rename your function to something like "EmptyInputs" to make your code a little more self-documenting. "CheckInputs" is a little non-descriptive.

Answer 2

You CheckInputs() functions logic is incorrect. Or will return true if any one condition is meet. To get your desired result you can either ask does:
If Condition1 = true AND Condition2 = true AND ....
Otherwise you can ask If Condition1 = false OR Condition2 = false OR ....
Try this....
Function isFormValid() As Boolean
If isTextFieldInvalid(Me.SANumber) Or isTextFieldInvalid(Me.SerialNumber) Or isTextFieldInvalid(Me.CustomerName.Value) Or Me.LyoSize.Value = Null Then
isFormValid = False
Else
isFormValid = True
End If
End Function
Function isTextFieldInvalid(FieldControl) As Boolean
If Not IsNull(FieldControl) Then
If Len(Trim(FieldControl.Value)) Then
isFieldValid = True
End If
End If
End Function
'Import MCL Files Code
Private Sub ImportMCL_Click()
On Error GoTo ErrorHandler
'disable ms access warnings
DoCmd.SetWarnings False
If isFormValid Then
MsgBox "All inputs must be entered!"
Exit Sub
Else
'load spreadsheet in .xls format
DoCmd.TransferSpreadsheet acImport, 8, "_MCL_UPLOAD", selectFile(), True
DoCmd.OpenQuery "UpdateMCL"
Call InsertInto_MASTER_UPLOAD
Call Delete_MCL_UPLOAD
MsgBox "MCL Imported Successfully!"
're-enable ms access warnings
DoCmd.SetWarnings True
End If
Exit Sub
ErrorHandler:
MsgBox "There was an Error: " & Err & ": " & Error(Err)
End Sub

Answer 3

Also, if you're clearing out afterwards by going something like SANumber = "" then testing for Nulls might not work. I'd check for both nulls and blanks. This is a general template you could use.
Dim LResponse As Integer
If (Nz(Me.SANumber.Value) = "") Then
MsgBox "Please enter a SA Number.", vbCritical + vbOKOnly, "Error"
ElseIf (Nz(Me.SerialNumber.Value) = "") Then
MsgBox "Please enter a Serial Number.", vbCritical + vbOKOnly, "Error"
'All criteria met
Else
LResponse = MsgBox("Would you like to submit? ", vbQuestion + vbYesNo, "Question")
If LResponse = vbYes Then
'enter code here
ElseIf LResponse = vbNo Then
MsgBox ("Not submitted.")
End If
End If