Set DataSource at Runtime

khh

I want to use (one TfrxReport and one TfrxDBDataset) for all my reports

1- Is this code valid?

because i get an error and it not seem to update fields names when changing dataset at runtime!!

...
    frrMain: TfrxReport;
    frdMain: TfrxDBDataset;
...

case StrToInt(rpt) of
    101 : ds := 'dsQ1;
    102 : ds := 'dsQ2';
    103 : ds := 'dsQ3';
 end;

  if ds <> '' then
  begin
    frdMain.DataSource.Name := ds;
  end;


  frrMain.LoadFromFile(CurrPath + 'rpts\' + rpt + '.fr3');
  frrMain.ShowReport;

2- How I can build a report with field names only without writing TfrxDBDataset name in memo?

gordk

Generally while you may use 1 report component you will probbably find you use more than 1 frxdbdataset or fruserdataset. in apps.
however one can switch the datasets connection the main trick is to also change the frxdbdatasets username.

ie rpt 1 uses frxdbdataset1 user name qry1
enabled dataset will appear as qry1
fields will appear as [qry1."fieldname"].
and will be the only dataset available to the report.

rpt uses frxdbdataset1 username qry2
enabled dataset will appear as qry2
fields will appear as [qry2."fieldname"].
and will be the only dataset available to the report.



this bit of code is probably your problem
if ds <> '' then
begin
frdMain.DataSource.Name := ds;
end;
what you are doing here is setting a dataset to the report component itself.
this would only be used when running a multi design page report.

khh

Currently I use one frxDBDataset with same username for all my reports. I change datasource for it at designtime and there is no problem.

How I can change datasource and update field list at runtime?!!

gordk

assuming the report was designed and saved all the datainfo is stored in the fr3 file.

so just switch the frxdbdatasets dataset or datasource prop before loading the report.

ie
datamodule repdat contains 2 ttables 2 tdatasource 1 tfrxdbdataset

procedure TForm1.Button1Click(Sender: TObject);
begin
repdat.frxDBDataset1.DataSource := repdat.ordds; // swith ds
frxreport1.Clear;
frxreport1.LoadFromFile('orders.fr3'); //load
frxreport1.ShowReport;
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
repdat.frxDBDataset1.DataSource := repdat.custds;
frxreport1.Clear;
frxreport1.LoadFromFile('Customer.fr3');
frxreport1.ShowReport;
end;

khh

Thank you.

It is working now.