trying to minimize Write Conflicts in a multi-user database

I have a multi-user Access 2003 database and lately a number of our users
are running into the Write Conflict message gives them the choice to either
Save Record, Copy to Clipboard or Drop Changes.

The problem occurs in a tabbed form with subforms on the different pages.

I have been told by several developers that one way to minimize the
occurrence of the Write Conflict is to put the main form's controls into a
subform and remove the Record Source from the main form. You then set Child
and Master Field links in the subforms to the value returned by the record
selection combo box on the main form (stored in a text box on the main
form).

In effect, you'd only have one record open at a time from the parent table
instead of loading multiple records into the the main form at once.

Would this in fact help reduce the number of Write Conflicts? I ask because
there are a number of events in the main form the various subforms what
would have to be modified, and I'd like to confirm that it will accomplish
something before I spend the time making those changes.

Thanks in advance,

Paul

I have a similar set up, but I only have one record open on the parent form at
any time. The user selects from a combobox (or by a search that presents them
with a limited number of records). I use this information to identify which
main record they want. Then I execute a query that returns JUST that one
record to the main form.

It is very fast and works nicely and almost no conflicts ever occur.

John Spencer
Access MVP 2002-2005, 2007-2010
The Hilltop Institute
University of Maryland Baltimore County

Paul wrote:
I have a multi-user Access 2003 database and lately a number of our users
are running into the Write Conflict message gives them the choice to either
Save Record, Copy to Clipboard or Drop Changes.

The problem occurs in a tabbed form with subforms on the different pages.

I have been told by several developers that one way to minimize the
occurrence of the Write Conflict is to put the main form's controls into a
subform and remove the Record Source from the main form. You then set Child
and Master Field links in the subforms to the value returned by the record
selection combo box on the main form (stored in a text box on the main
form).

In effect, you'd only have one record open at a time from the parent table
instead of loading multiple records into the the main form at once.

Would this in fact help reduce the number of Write Conflicts? I ask because
there are a number of events in the main form the various subforms what
would have to be modified, and I'd like to confirm that it will accomplish
something before I spend the time making those changes.

Thanks in advance,

Paul

Then it sounds like it's well worth the time to make the changes.

Thanks, John.


"John Spencer" wrote in message
...
I have a similar set up, but I only have one record open on the parent form
at any time. The user selects from a combobox (or by a search that
presents them with a limited number of records). I use this information to
identify which main record they want. Then I execute a query that returns
JUST that one record to the main form.

It is very fast and works nicely and almost no conflicts ever occur.

John Spencer
Access MVP 2002-2005, 2007-2010
The Hilltop Institute
University of Maryland Baltimore County

Paul wrote:
I have a multi-user Access 2003 database and lately a number of our users
are running into the Write Conflict message gives them the choice to
either Save Record, Copy to Clipboard or Drop Changes.

The problem occurs in a tabbed form with subforms on the different pages.

I have been told by several developers that one way to minimize the
occurrence of the Write Conflict is to put the main form's controls into
a subform and remove the Record Source from the main form. You then set
Child and Master Field links in the subforms to the value returned by the
record selection combo box on the main form (stored in a text box on the
main form).

In effect, you'd only have one record open at a time from the parent
table instead of loading multiple records into the the main form at once.

Would this in fact help reduce the number of Write Conflicts? I ask
because there are a number of events in the main form the various
subforms what would have to be modified, and I'd like to confirm that it
will accomplish something before I spend the time making those changes.

Thanks in advance,

Paul

John,

After reading your message again, it occurred to me I would simplify things
a lot if I kept the main form data there in the main form like you said you
were doing it instead of moving it into a subform like I had planned. If I
did that, what's the best way to load a single record into the main form
from the After Update event of a combo box?

Would it be:

DoCmd.OpenForm stDocName, , , stLinkCriteria

or is there a better way to do it?

Thanks again in advance,

Paul



"John Spencer" wrote in message
...
I have a similar set up, but I only have one record open on the parent form
at any time. The user selects from a combobox (or by a search that
presents them with a limited number of records). I use this information to
identify which main record they want. Then I execute a query that returns
JUST that one record to the main form.

It is very fast and works nicely and almost no conflicts ever occur.

John Spencer
Access MVP 2002-2005, 2007-2010
The Hilltop Institute
University of Maryland Baltimore County

Paul wrote:
I have a multi-user Access 2003 database and lately a number of our users
are running into the Write Conflict message gives them the choice to
either Save Record, Copy to Clipboard or Drop Changes.

The problem occurs in a tabbed form with subforms on the different pages.

I have been told by several developers that one way to minimize the
occurrence of the Write Conflict is to put the main form's controls into
a subform and remove the Record Source from the main form. You then set
Child and Master Field links in the subforms to the value returned by the
record selection combo box on the main form (stored in a text box on the
main form).

In effect, you'd only have one record open at a time from the parent
table instead of loading multiple records into the the main form at once.

Would this in fact help reduce the number of Write Conflicts? I ask
because there are a number of events in the main form the various
subforms what would have to be modified, and I'd like to confirm that it
will accomplish something before I spend the time making those changes.

Thanks in advance,

Paul

I'm working on implementing John Spencer's description of a parent form that
has only one record open at a time, and three questions occur to me:

1. Do you use DoCmd.OpenForm stDocName, , , stLinkCriteria in the
AfterUpdate event of a combo box to move between records?

2. You would be using a SQL SELECT statement to populate the combo box used
to navigate between records once the form is open, but how do you determine
which record to open when you initially load the form? That is, how do you
extract the value of the first record (or for that matter, any record) in
that SQL statement to use as the stLinkCriteria when you first open the
form?

3. Since the main form has only one record loaded at any time, the normal
navigation buttons won't be able to do anything. Are there any Web sites
that address building custom navigation buttons for single-record forms?

Thanks in advance,

Paul

I'm not sure about question 3 (I haven't done this before, but I will
certainly keep it in mind, it seems an excellent idea).

For question 1), you wouldn't be using the boilerplate DoCmd.OpenForm method
and criteria... you presumably already have the form open, you just need to
give it a recordsource...

Private Sub Me.cboRecords AfterUpdate()
Me.Recordsource = "SELECT * FROM table WHERE [ID] = " & Me.cboRecords
Me.Requery
End Sub

Ideally, this would be a saved query name that pulls the value direct from
the combo on the form... performance would be better like that, I believe.

As for Q2, it depends what you want your first record to be... but what I
would do is move the above code into its own procedure rather than the
afterupdate, then you can call the procedure from both the Open event and the
combo AfterUpdate event:


Private Sub psGoToRec(lRecID As Long)
Me.Rowsource = "SELECT * FROM Table WHERE [ID] = " & lRecID
Me.Requery
End If

Private Sub cboRecord_AfterUpdate()
psGoToRec(lRecID)
End Sub

Private Sub Form_Open(Cancel As Integer)
psGoToRec(your default opening id here)
End Sub



I would be curious to see a reply for the navigation (and new records)
portion of the question... no lights are shining in my head on that at the
moment...
--
Jack Leach
www.tristatemachine.com

"I haven''t failed, I''ve found ten thousand ways that don''t work."
-Thomas Edison (1847-1931)



"Paul" wrote:

I'm working on implementing John Spencer's description of a parent form that
has only one record open at a time, and three questions occur to me:

1. Do you use DoCmd.OpenForm stDocName, , , stLinkCriteria in the
AfterUpdate event of a combo box to move between records?

2. You would be using a SQL SELECT statement to populate the combo box used
to navigate between records once the form is open, but how do you determine
which record to open when you initially load the form? That is, how do you
extract the value of the first record (or for that matter, any record) in
that SQL statement to use as the stLinkCriteria when you first open the
form?

3. Since the main form has only one record loaded at any time, the normal
navigation buttons won't be able to do anything. Are there any Web sites
that address building custom navigation buttons for single-record forms?

Thanks in advance,

Paul


.

Thanks for the help with this, Jack. The code you suggested:

Me.Recordsource = "SELECT * FROM table WHERE [ID] = " & Me.cboRecords

works great in the combo box's AfterUpdate event because it retrieves the
desired record instantly, and leaves only the single record in the form,
which is exactly what I want.

However, I'm having trouble getting it to work in the form's Load event
because the combo box is null, and the assignment statement above results in
an error since Me.cboRecords is null. Similarly, if I try to put the value
of the combo box in the criteria field of the form's query, the form is
blank because the value in the combo box is null. Is there any way I can
force the combo box to retrieve one of its own records (the first one would
be ok) as soon as the form loads, so it can provide a non-null value for the
ID in the assignment statement and the criteria of the form's query?

I've tried to Requery the combo box before setting the RecordSource of the
form, but that didn't seem make a difference.

Any suggestions how I can overcome problem of the empty combo box when the
form loads?

Paul

just a sanity check as to whether this string is purely theoretical or not.
Have done many many multi user applications with nary a write
conflict....Access out of the box works really well in this area and so I
wonder if the issue is theoretical or real....

"Paul" wrote:

I have a multi-user Access 2003 database and lately a number of our users
are running into the Write Conflict message gives them the choice to either
Save Record, Copy to Clipboard or Drop Changes.

The problem occurs in a tabbed form with subforms on the different pages.

I have been told by several developers that one way to minimize the
occurrence of the Write Conflict is to put the main form's controls into a
subform and remove the Record Source from the main form. You then set Child
and Master Field links in the subforms to the value returned by the record
selection combo box on the main form (stored in a text box on the main
form).

In effect, you'd only have one record open at a time from the parent table
instead of loading multiple records into the the main form at once.

Would this in fact help reduce the number of Write Conflicts? I ask because
there are a number of events in the main form the various subforms what
would have to be modified, and I'd like to confirm that it will accomplish
something before I spend the time making those changes.

Thanks in advance,

Paul


.

No, this is a real issue for me. I've spent the last year working on a very
real project management database in Access 2003. At the moment, I have 40
users, and a week from Monday, I'm going to have about 100. Just within the
past three weeks, my users have started to encounter the Write Conflict
error I described in my first post.

I work in a very real state government agency. My colleagues are using it
to manage their projects, and I'll list (hey - you asked if it was real)
just a few of the features that make it more than a card filing system:

* Every night my VBA code runs 42 queries that append and update data in our
application from an Oracle database, SQL Server and another Access database.
They also upload different data to that other Access database.
* In addition to projects, it also manages leases, contacts, activity nd
documents.
* It uses the OS login name to distinguish between editable and read only
records, depending on whether the user is a team member of the project
* there are 5 user classes - user, admin, admin User, read only and a 5th
one that I can't recall at the moment - and depending on which class the
user belongs, different forms and different form controls will be presented
to the user.
* It's also a document processing file manager. My users process lots of
contracts and documents, and my application enables them to select from
hundreds of documents in Word, Excel, PDF and html from a shortcut menu
sysem, and it populates fields in the documents with data in the database.
It also saves the files into the project folder on the network drive, so the
user doesn't have to navigate through Windows explorer to find the project
folder.

We have conservatively estimated that the file management module I just
described is saving our agency and the taxpayer the time equivalent of over
$500,000 per year.

Maybe you don't have a problem because you designed your database better
than I did. I do have memo fields in two tables, and Tom Wickerath has
pointed out that could be the problem.

But yes, it's a real database, and I'm dealing with a very real problem.

Paul

Paul wrote:
No, this is a real issue for me. I've spent the last year working on a very
real project management database in Access 2003. At the moment, I have 40
users, and a week from Monday, I'm going to have about 100. Just within the
past three weeks, my users have started to encounter the Write Conflict
error I described in my first post.

Other posters has given you many excellent advices. I just want to rule
out one more cause of write conflict: It is possible that the write
conflict errors are bogus because of VBA coding stepping on itself or on
the Access. A good way to do this is to have VBA execute a separate
query that modifies the same record that is being edited in the form.
This comes out as two separate connection and of course the software
(whether it's Access or the backend RDBMS) has no idea that the two
separate connection are actually the same application/user and perceive
it as deadlock for this reason.

Therefore, if your VBA code behind the forms does use queries that
update the same record or maybe different record on the same table that
could be on the same page, this will cause write conflicts.

If your code doesn't have that, then you're probably good and want to
look at others' excellent solutions.

Best of luck.