🚀 go-pugleaf

"Paul Ferrara" <paul@nospam.columbusoft.com> wrote in message
news:8ej96l02qr0@news2.newsguy.com...
> I think you're going to have to change the DataSet property of all your
> DataSources.  I can't think of a way to do that at run-time without if
> statements.

I'm not sure about what do to at design time (possibly a tDataSet descendant
whoose constructor redirected the construction to the appropriate
BDE/Advantage constructor), but at run time the following should work.


type tForm1 = class (tForm)
    . . .
    private
        fMyDataSet        : tDataSet;
    . . .
    end;


procedure tForm1.FormCreate (Sender : tObject);

begin
if UsingBDE {you'll have to work this one out}
then begin
    fMyDataSet := tTable.Create (Self);
    {assign SessionName, DatabaseName, TableName and other BDE required
properties}
    end
else begin {assuming only two table types}
    fMyDataSet := tADSTable.Create (Self);
    {assign the Advantage required properties}
    end;
{hook the dataset to the datasource}
DataSource1.DataSet := fMyDataSet;
fMyDataSet.Open;
end;

Of course one has to include both the BDE and Advantage db engine in the
release. (Also DBTables and the Advantage equivalent(s) have to be in the
Implementation section Uses clause.) I don't know about Advantage, but
AFAIR, DBTables has an initialization section does some work with sessions
but I can't recall if it ends up starting the BDE or if that only occurs
when the first BDE table is openned.

At design time one might be able to work with a component whoose
construction looked something like:

class function tMyDataSet.NewInstance : tObject;

begin { override so that no memory is allocated }
//
end;

constructor tMyDataSet.Create (anOwner : tComponent);

begin
if UsingBDE
then Self := tMyDataSet (tTable.Create (anOwner))
else Self := tMyDataSet (tADSTable.Create (anOwner));
end;

Other than known that this compiles, (and with a very simple test works), I
really don't know all the ramafications of using it. So caution would be
advised.


>
> Paul / ColumbuSoft
> www.columbusoft.com
>
>
> Nick Ring <nring@NOSPAM.smf.com.au> wrote in message
> news:390cccae.6779618@postoffice...
> > Hello,
> >
> > What I would like to do is the following (in a nutshell) : Depending
> > if I'm running on a local machine or not, I would like to use BDE's
> > TTable (if running on a local machine), otherwise use Advantage's
> > TAdsTable.
> >
> > How ever, I don't want to use a large amount of IF statements all
> > through my code to figure out if I'm using a TTable or a TAdsTable.
> >
> > Is there a way to have the table I'm using (be it a TTable or a
> > TAdsTable) assigned to a single variable and use it with out having to
> > figure out what type it is before using it??
> >
> > Thanks for any help in advance,
> > Nick
>
>