[fpc-devel] Adding a unidirectional dataset to sqldb

[Martin Schreiber]

On Thursday 05 October 2006 22.41, Joost van der Sluis wrote:
> > > Now I'm thinking about using an interface, to avoid double code. But I
> > > don't know what effect that has on run-time performance. I mean, the
> > > idea was to make if faster ...
> >
> > A very good idea! It can then be implemented by a common worker class.
> > TSQLConnection and TSQLTransaction should be independent of TSQLQuery and
> > TSQLQuery should get its own unit.
>
> Can you explain to me how I should construct this worker-class? As
> Michael said, my solution won't work...
>
If TSQLConnection or TSQLTransaction need callbacks into TSQLQuery and 
"TSQLQueryUni" do it by an corba interface (at the first glance I didn't see 
any).
To implement the common functions of TSQLQuery and TSQLQueryUni use a "worker 
class" which does callbacks by an corba interface.
See for an example tdscontroller and tmsesqldb in MSEgui which I used to 
implement different DB workarounds and extensions.

http://svn.sourceforge.net/viewvc/mseide-msegui/trunk/lib/common/db/
msedb.pas, msesqldb.pas.

Martin