[AccessD] MoveFirst needed in DAO?

Hi Darryl

True, if you need a precise count, you have to do a MoveLast.

However, in most cases I don't care how many records, I just need to loop these. If you just have opened a DAO recordset, I've never seen anything else than it was positioned at the first record. Thus, I don't even have to check for records:

  Set rst = dbs.OpenRecordset(strSQL)
  While rst.EOF = False
    ' do something
    rst.MoveNext
  Wend

because if the recordset is empty, the loop is skipped.
Of course, if the loop runs and you will then run another loop, you then have to move to the first record:

  If rst.RecordCount > 0 Then
    rst.MoveFirst
  EndIf

So I was just wondering if anyone had experienced situations where the recordset right after the initial opening was positioned anywhere else than the first record. It doesn't seem so.

/gustav


>>> darryl at whittleconsulting.com.au 09-08-12 1:34 >>>
In many instances I have need to know how many records are found, to do that you need to movelast then movefirst.  Especially if you are then going to loop thru those records.  Of course, often you don't care how many are found and a >0 count will do.

If I am going to loop I will always put in a  MoveFirst to be sure it is at the top.  Maybe redundant?

-----Original Message-----
From: accessd-bounces at databaseadvisors.com [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Dan Waters
Sent: Thursday, 9 August 2012 12:41 AM
To: 'Access Developers discussion and problem solving'
Subject: Re: [AccessD] MoveFirst needed in DAO?

I've always seen that in a newly opened DAO recordset, the recordset is always positioned at the first record - IF THERE ARE ANY RECORDS!

So for most recordsets a check to see if any records exist is needed.

Dan

-----Original Message-----
From: accessd-bounces at databaseadvisors.com
[mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Charlotte Foust
Sent: Wednesday, August 08, 2012 9:17 AM
To: Access Developers discussion and problem solving
Subject: Re: [AccessD] MoveFirst needed in DAO?

In DAO, the newly opened recordset is positioned at BOF but not necessarily on a record, IIRC.

Charlotte

On Wed, Aug 8, 2012 at 2:09 AM, Gustav Brock <gustav at cactus.dk> wrote:

> Hi all
>
> Having opened a DAO recordset:
>
>     Set rst = dbs.OpenRecordset(strSQL)
>
> often the first code line following is:
>
>     rst.MoveFirst
>
> or, if the recordset can be empty:
>
>     If rst.RecordCount > 0 Then
>       rst.MoveFirst
>     EndIf
>
> But is that really necessary? At which record could the recordset 
> possibly be positioned if not at the first?
>
> Even a snapshot or an ODBC linked recordset will not - as far as I 
> know - move anywhere until you tell it to do so.
>
> For ADO recordsets it is different as the recordcount can be -1 until 
> you, for example, have done a MoveLast.
>
> /gustav