If it is true, how can I design a multi-user database application?

In my case, the data which edited and posted in a transcation can't
be read/view by other user. If the record in the first record of
master table, the IBOQuery of detail table can't be open.

Thanks for help!

Earnest

--- In IBObjects@yahoogroups.com, Hans <hhoogstraat@...> wrote:
>
> Think that is in FB database design
>
> ----- Original Message -----
> From: "earnesttse" <earnesttse@...>
> To: <IBObjects@yahoogroups.com>
> Sent: Wednesday, March 19, 2008 10:43 PM
> Subject: Re: [IBO] IBOQuery with record locking
>
>
> > Dear Jason,
> >
> > As I know, if one user edited and posted a record in a
transaction,
> > beofore the user to commit the transaction, other user can see the
> > latest commited version of record, right?
> >
> > My problem is that in this case the secord can't be read or
opened by
> > other user. The second user want to read the record only, not to
edit
> > or delete. When the second user to read the record, IBO raise a
> > record lock conflict error.
> >
> > I tried this:
> >
> > 1. User A: StartTransaction -> Insert one master record or one
detial
> > record -> post both master and detail record -> comit the
transaction
> > 2. User B can read about records.
> > 3. User A: StartTransaction -> edit master record -> edit detail
> > record and post it
> > 4. User B: open IBOQuery of master table without problem
> > 5. User B: open IBOQuery of detail table -> this IBOQuery can't be
> > open untill User A call commit or rollback
> >
> > I found that the system stoped at line 6321 of IBODataset.pas:
> > InternalDataset.BufferRowNum := FCurRowNum + 1; After User A call
> > commit or rollback, the system will run again.
> >
> > My question is: why the code (InternalDataset.BufferRowNum :=
> > FCurRowNum + 1;) causes record locking conflict?
> >
> > Thanks for help!
> >
> > Earnest
> >
> >
> >
> > --- In IBObjects@yahoogroups.com, "Jason Wharton" <supportlist@>
> > wrote:
> >>
> >> It sounds like what you are asking for is a dirty read.
> >> This is not something that InterBase or Firebird allows.
> >> This is also something that is not desirable.
> >> If you want another user to be able to see changes from another
> > user then
> >> they have to be committed and in a tiCommitted isolation.
> >>
> >> Jason Wharton
> >>
> >> > -----Original Message-----
> >> > From: IBObjects@yahoogroups.com
[mailto:IBObjects@yahoogroups.com]
> > On
> >> > Behalf Of earnesttse
> >> > Sent: Wednesday, March 19, 2008 7:01 PM
> >> > To: IBObjects@yahoogroups.com
> >> > Subject: [IBO] IBOQuery with record locking
> >> >
> >> >
> >> > Hello, I have a record locking problem needing your help!
> >> >
> >> > I have master/detail tables to record sale invoice. I call
> >> > IB_Database.StatTransaction before editing master reocrd. When
one
> >> > user is editing a record of detial, other user can't read the
> > edited
> >> > record, system will wait until the record has been cancelled or
> >> > posted.
> >> >
> >> > Is there any way to allow the second user to view the edited
> > record
> >> > without waiting the first user completed editing?
> >> >
> >> > I read the book of Helen: The Firebird Book. I found that in
page
> >> > 552: In Firebird, all updates are at row level ... When a
> > transaction
> >> > submits a request to update a row; the old version of that row
> >> > remains visible to all transactions. Writers do not block
readers.
> >> >
> >> > Is there anything I missed?
> >> >
> >> > I am using Delphi 2007, IBO 4.8.7, IBOQuery, AutoCommit=True,
> >> > Isolation=tiCommitted.
> >> >
> >> > Your prompt reply is highly appreciated!
> >> > Thanks for help!
> >> >
> >> >
> >> > Earnest
> >>
> >
> >
> >
> > ------------------------------------
> >
> >
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