MS Access Form Bind to ADO Recordset

Question

Driving me bonkers...

The problem is one of speed.

I have a working SQL Server linked to a client accessible website, which I am wanting to add an Access front end to enable us office bound staff to better support both client and field staff.

The current form I have constructed is a main form with five sub forms contained within it, giving us all the relevant client information in one view. This works however is taking 24 seconds to load a single clients complete records.

I have looked at the SQL Server and found the absence of indexes, fixed this and got the time down to 24 seconds with consequent loads closer to 18 seconds depending on the client (some have a lot more records). This might be okay, as whilst this is a relative eternity in computing time in real world time its okay...but not great. I would like to see if I can get a better load by changing the way I connect and how the form is bound to the records etc.

In looking at the various ideas and reading a lot I found: https://docs.microsoft.com/en-us/office/vba/access/concepts/activex-data-objects/bind-a-form-to-an-ado-recordset?source=docs

Which appealed to me as I am more inclined to use ADO, seldom if ever to I use DAO. ADO I understood originally was intended to use with SQL and so on, and it seems like a sensible idea.

Again as I understand it if I can get this to work it will act as a pass through query returning only one record over the net and should consequently speed my form up considerably. However it wont work.

My code is:

Private Sub cssSetForm(lngID As Long)
Dim cnn As New ADODB.Connection
Dim Rs1 As New ADODB.Recordset
Dim strSQL As String
Dim strR As String  

cnn = "Provider=MSOLEDBSQL;Server=Server;Database=DatabaseName;UID=UserName; PWD=Password;"   
cnn.Open

  strSQL = "SELECT Clients.Clientid, Clients.AccountContact, Clients.AccountEmail, Clients.Address, Clients.Name, Clients.OfficePhone, Clients.PostCode, " & _
           "Clients.ShentonAcc, Clients.Suburb FROM Clients WHERE (((Clients.Clientid)=" & lngID & "));"



    With Rs1

        Set .ActiveConnection = cnn
        .Source = strSQL
        .LockType = adLockPessimistic
        .CursorType = adOpenKeyset
        .Open

    End With


     Debug.Print Rs1.RecordCount

   Me.Recordset = Rs1

  End sub

Now I am getting no errors until Me.Recordset=rs1 which is generating an error 3251 Operation is not supported for this type of object which is very nice for someone that understands why this is not supported when it is no different than I can see to the example I was copying from.

I don't understand why the form I am working on doesn't support recordsets according to the error message? Is there an error in my code? Is the error in my understanding of the destructions from the linked site? Is the error something else?

Thanks for the help

Answer 1

Well, loading up 5 sub forms is a lot of data pulling. converting to ado reocdsets is NOT going to speed this up.

What you want to do here is NOT load up the sub forms until such time the user say clicks on the appropriate tab to load the one given sub form.

As long as the form in question is opened with a were clause, then the one main form will ONLY pull the one main record from sql server. So doing all kinds of fancy reocrdsets etc. will gain you next to nothing. So, always - but always launch your main form to the one record. If that main form is bound to a table of 5,000 rows, or 1 million rows, it will load instant despite the fact that the form is bound directly to the linked table with 1 million rows.

With this one main form, you edit or do whatever, and then close it. You are then of course right back to the search form/prompt you have to ask the user what reocrd to work on. So, how a accouting package works, or even google? You search, display the search resutlts and pick ONE thing to view. This approach should get your main form load down to about 1 second. Again, just use the "where" clause when you open that form: eg:

dim strInv   as string
strInv = InputBox("Enter invoice number to view")
docmd.OpenForm "frmInvoice",,,"InvoiceNum = " & strInv

Of course the above is air code, and you will likely build some search form say like this:

So in above, the user types in a bit of the name. We then fill the form with a simple where clause, or

me.MySubForm.RecordSource = "select * from tourCust where LastName like '" & sTextbox & "*'"

When a user clicks on the glasses icon to edit + view the ONE row, we use this:

docmd.OpenForm "frmDetails",,,"id = " & me!id

Again, all bound forms, and dispite the tables having 500,000+ rows, the loading of the forms is instant - even when the back end is SQL server.

So, adopt a prompt + search results + edit/view design pattern. EVERY single software system has this loop or design pattern. Not only is it user friendly, it also performs well since access DOES NOT pull the whole table, but ONLY the reocrds you tell the form to load by using the where clause as per above.

Now, for the child forms (sub forms). As noted, don't load them until the user actually clicks on the given tab.

So, in the on-change event of the tab, you can go:

If Me.TabMainpage.Pages(Me.TabMainpage).Name = Me.pgeDocs.Name Then

'' the tab been changed to show past tours
dim strSQL as string
strSQL = "select * from tblPastTours where tour_ID = " & me!ID
me.
' dynamic load the sub form
If Me.frmSubPastTours .SourceObject = "" Then
     Me.frmSubPastTours.SourceObject  = "Forms.frmPastTours"
End If
' now load sql into form
 me.frmSubPastTours.Form.RecordSource = strSQL

The above is mostly air code, but the idea here is:

don't load the sub form until you need to. OR YOU can have the sub form load, but leave its RecordSource blank and STUFF in the sql you need for display WHEN you click on the tab.

It is possible that you need all sub forms to display. You could thus leave all sub form RecordSource blank, and then it the main form on-load event, simply stuff in the sql to each sub form. This might improve speed a bit, and with your slower connection this would be the least amount of work.

You "fail" to mention how you launch + load the main form, but as noted, it should be opend to the ONE reocrd. The link master/child pulling of data can be bit slow, and I can't say JUST using the above sql stuff into those forms will help a lot. I would try that first as it is the least amount of work. If load time is still too slow, then placing te sub forms behind a tab control and ONLY loading the sub form, and then setting the datasource will be the fastest.

Attempting to build all those recordsets, and then bind them to a form? It not speed things up, and just shoving a sql string into the form (or sub form) recordSource amounts to really the SAME thing and same performance anyway. So, you save tons of work and code, and quite much the above idea not only applies to sql server back ends, but we all VERY often dynamic load sub-forms and don't load them until such time you view the sub form say behind a tab control.