October 2006 ~ LEARN MS-ACCESS TIPS AND TRICKS

Introduction

This is an image of the Main Switchboard Screen, where a Reminder Ticker is active and scrolls with a continuous stream of information. The Automotive Sales & Service Company enters into Vehicle Service Contracts with Corporate Customers for various periods and maintains the data in an MS-Access Database. Every month a few Vehicle Contracts are due for renewal and the Staff concerned have to contact those Customers and check whether they would like to renew their Maintenance Contract with the Company or not.

The Reminder Ticker displays the Customer Code, Vehicle Model, Chassis Number, Vehicle Description, and Expiry Date (not yet moved into the visible area of the Ticker).

The Input Data for the Ticker is extracted from the Vehicle Maintenance Contract Table based on the Expiry Date falling within the current month, with the help of a Query. Customer Code, Vehicle Model Number, Chassis Number, Vehicle Description & Expiry Date Values of each contract record is concatenated into a Variant Variable (String Variable may limit the length of the String to 255 characters) and used for the Ticker with the help of Timer.

The VBA Code

The VB code that does this trick is given below:

Option Compare Database 
Option Explicit 
'Global Declaration 
Dim strTxt  
Private Sub Form_Open(Cancel As Integer) 
Dim db As Database, rst As Recordset 
Dim rstcount As Integer, currMonth As Integer, marqMonth  
On Error GoTo Form_Open_Err  
currMonth = Month(Date)  
' Expiry_Marque is a parameter Table which holds  
' the Start-Date & End-Date of Current Month and uses to pick  
'the Contract Expiry Cases falls within this period.  

marqMonth = Month(DLookup("ExpDateTo", "Expiry_Marque"))  
If currMonth   marqMonth Then  
' when the month is changed the parameter table is  
' updated with changed period. 
' i.e. Start-Date and End-Date of the Current Month  
DoCmd.SetWarnings False 
DoCmd.OpenQuery "Expiry_Marque_Updt", acViewNormal 
DoCmd.SetWarnings True 
End If  
'checks whether any contract expiry cases are there 
'during the month.  

rstcount = dCount("*", "Expiry_MarqueQ")  
If Nz(rstcount, 0) = 0 Then
  strTxt = String(60, " ") & "*" NO CONTRACT EXPIRY CASES FOR "
  strTxt = strTxt & Format(Date, "mmmm yyyy") & " **"  
GoTo Form_Open_Exit
End If  
' builds the String strTxt with ticker data.  
Set db = CurrentDb 
Set rst = db.OpenRecordset("Expiry_MarqueQ", dbOpenDynaset)
  strTxt = String(60, " ") & "Expiry Cases:"
  Do While Not rst.EOF  
     With rst
 strTxt = strTxt & " ** {" & rst.AbsolutePosition + 1 & "}. CUST: ["
        strTxt = strTxt & ![CUST_COD] & "] MODEL :[" & ![MODL_COD]
        strTxt = strTxt & "]  CHAS :[" & ![CHASSIS] & "](" & ![DESC]   
        strTxt = strTxt & ") EXP.: " & ![EXP_DATE]
 End With
  rst.MoveNext
  Loop
  rst.Close  
'A Text Box on the Form is set with the Total Number 
'of Contracts getting expired.
  Me![mVehl] = rstcount & " Vehicles."  
' the Timer is invoked and the time to refresh  
' the control is set with quarter of a 
' second. This value may be modified.
Me.TimerInterval = 250 
Set rst = Nothing 
Set db = Nothing  
Form_Open_Exit: 
Exit Sub  
Form_Open_Err: MsgBox Err.Description, ,"Form_Open" 
Resume Form_Open_Exit 
End Sub   

Private Sub Form_Timer() 
Dim x  
On Error GoTo Form_Timer_Error  
x = Left(strTxt, 1)  
strTxt = Right(strTxt, Len(strTxt) - 1)  
strTxt = strTxt & x  
' Create a Label with the Name lblmarq  
' on your Form to scroll the values 
' The value 200 used in the Left Function may be 
' modified based on the length of the 
' Label. Format the Label with a fixed width font 
' like Courier New so that you can correctly determine 
' how many characters can be displayed on the legth 
' of the Label at one time and change the value accordingly.  

lblmarq.Caption = Left(strTxt, 200)  

Form_Timer_Exit: 
Exit Sub  
Form_Timer_Error: 
MsgBox Err.Description, , "Form_Timer_Error" 
Resume Form_Timer_Exit  
End Sub

Ticker Active/Inactive States

The code starts running immediately after opening the form and runs continuously, till you close the form.

When the Form becomes inactive, after you open some other Form over it, the Ticker is deactivated. If nobody is watching there is no point in keeping running the Program. When the Form becomes active again the ticker starts running again. To add this capability to the reminder ticker copy and paste the following Code also into the Form Module:

Private Sub Form_Deactivate()
     Me.TimerInterval = 0
End Sub

Private Sub Form_Activate() 
Me.TimerInterval = 250 
End Sub

Download

You can download a demo sample database from the download link given below:

Download Demo Database

Private Sub cmdBrowse_Click() Dim VFile As String On Error GoTo cmdBrowse_Click_Err ChDrive ("C") ChDir ("C:\") cmDialog1.Filter = "All Files (*.*)|*.*| _ Text Files (*.txt)|*.txt|Excel WorkBooks (*.xls)|*.xls" cmDialog1.FilterIndex = 1 cmDialog1.Action = 1 If cmDialog1.FileName = "" Then VFile = cmDialog1.FileName Me!lbldb = VFile End If cmdBrowse_Click_Exit: Exit Sub cmdBrowse_Click_Err: MsgBox Err.Description, , "cmdBrowse_Click" Resume cmdBrowse_Click_Exit End Sub