Hi

When developing an application its not uncommon to manually open an SQL component to see the results in a table (e.g. to order/format the columns). As noted you need to make sure that you close sql's, set connected=FALSE on any database components and active=false on any clientdatasets as soon as possible, and certainly before releasing the program. That said, if you don't the result is that your program may not run (because the form create will try and connect to your development database, which may not be available to 'normal' users) - I have never seen this stop the program from compiling.

The error you are reporting is a run-time error not a failure to compile. I suspect you have the database set as connected in the object inspector and at run time are trying to set the database parameters (database name, user name, etc) which you cannot do while it is connected.

Your comment about transactions is possibly to do with the way you handle database errors. if while debugging you stop the application mid-transaction, and then restart it and attempt to change a record locked by the still open transaction you are likely to get an error. depending on the database version and mode, a short network disconnect while you reboot your PC may not be enough for the database to recognise that you have aborted the original connection.

you need to make sure all your sql's are in a try/except block with a rollback in the except and avoid aborting the application before it has done the rollback on any errors.

since you have more than one program accessing the database I assume you have code to handle momentary conflicts.

--- In IBObjects@yahoogroups.com, Robert Martin <rob@...> wrote:
>
> Hi
>
> I suspect it is what Daniel suggested. At design time you are setting
> Connected to true. I dont use the IB_ components but I suspect it works
> the same as the IBO components. Most likely this is accidental, if you
> mannually change the property to true it can cause this error, but
> bringing up field / property editors on Query / table components will
> automatically set connected to true. This will cause your error.
>
> All you need do to get around this is to have code that always makes
> sure connected = false before attempting to connect. Also remember to
> make sure connected = false before doing a release build. Otherwise
> when you app starts it will try and connect to your dev DB which may not
> be in the same location / Alias on your clients machine.
>
> Hope this helps
> Rob
>
>
> On 1/06/2011 11:02 a.m., Terry Black wrote:
> > Hi, I have 2 Delphi applications that are working on the one Firebird
> > database. Let me explain. The first application uses 3 tables
> > relationally linked to each other. It is a many to many relationship.
> > This application has been working well for 6 months. The second
> > application is my developmental application which uses the same firebird
> > database which is looking at adding records to the 3 tables. So I am
> > constantly changing and compiling the second developmental application.
> > At some stage it hangs and then fails to compile. Giving me the
> > 'EIB_ConnectionError - Cannot change while connected'.
> > I can still use the original application which uses the same database.
> >
> > If I rebooted the computer my developmental application would still not
> > compile. So this looked like there was something wrong with my code in
> > the developmental application. However, I find this morning that it
> > compiles easily. I have not changed anything since it was unable to
> > compile yesterday.
> >
> > I am not sure what is happening. It looks like I opened a transaction
> > which for some reason would not close yesterday. This prevented my
> > developmental application opening the Firebird database. Today it is all
> > fine. I don't understand it.
> >
> >
> > Terry
> >
> >
> >
> >>>> Daniel Rail<daniel@...> 31/05/2011 10:00 pm>>>
> > Hi,
> >
> > At May-31-11, 4:26 AM, Svein Erling Tysvær wrote:
> >
> >> I think she meant that she thinks you're doing something like:
> >> TIB_Connection1.Connect;
> >> TIB_Connection1.Username:=...
> >> and you cannot change username or password when you're already
> >> connected. Actually, I don't think it has to be username or password
> >> that is changing, I think it can also be that you try to change the
> >> name of the database, maybe even the name of a database belonging to
> >> a started transaction (at least I doubt it is possible to close a
> >> connection whilst its transaction is running).
> >> You have to find the exact place in your code that causes the
> >> error, this kind of showstoppers luckily tend to be relatively easy
> >> to locate (and easy to understand why gives this error once you find
> > the exact line).
> >
> > It might also be that TIB_Connection.Connected := True at compile
> > time, and then trying to change the server and path at runtime.
> >
>