How to assign dataset dynamically to Fast report?

Question

Hi all,

I have created a report using Fast Report Designer and calling this using Delphi 6. But datasets for the master databad and the fields are not assinged at design time. Iwant to set these properties at runtime depends on the selected dataset. How can I do that. How can I access the dataset property of the master band in Delphi before calling the preview/print/design ? Added following code in frxReport1BeforePrint.

  t := frxReport1.FindObject('MasterData1') as TfrxMasterData;
  //if Assigned(t) then
    //t.DataSet := frxIBODataset1;

  m := frxReport1.FindObject('mTenderType') as TfrxMemoView;
  if Assigned(m) then
  begin
    m.DataSet := frxIBODataset1;
    m.DataField := 'ACCOUNTNAME';
    m.Text := '[frxIBODataset1."ACCOUNTNAME"]';
  end;

But I need to set these properties before calling the print/design/preview. Any help is appreciated.

Kind Regards Sinu

Answer 1

You should first specify whether you are trying to use a dataset defined in your application, or a dataset defined directly in your report (Data tab in FastReport designer)?

If you are trying to use a dataset which is defined inside your application (e.g. an AdoDataset instance defined in one of your data-modules), for such a purpose, you don't have to bind the MasterBand to your dataset. dynamically. Inside the report, your MasterBand is bound to a TfrxDbDataset instance in design time. At runtime, your frxDbDataset instance can be connected to any dataset in your project.

Here is how it would be:

1- You drop a frxReport component and a frxDbDataset component on your form or data-module. 2- In the report designer, you go to Datasets section, and add the available frxDbDataset to the report's dataset list. 3- You add a master-data band, and assign the frxDbDataset to its Dataset property. 4- Now in your code, before showing or preparing the report, you can write something like this:

  if MyOption = 1 then
    frxDbDataset1.Dataset := AdoDataset1
  else
    frxDbDataset1.Dataset := AdoDataset2;

Whatever you assign to frxDbDataset will be printed by the master-band in your report.

If you are defining the dataset directly inside the report, using FastReport designer; then everything is inside your report. Just open fastreport designer and do this:

1- Go to Data tab and define your datasets (e.g. AdoQuery1). 2- Select Report object from Report Tree pane. 3- In the object inspector go to Events tab. 4- Choose a proper event; OnStartReport is a good event for your job. Double-click on it to open the code editor. 5- Now you can assign the dataset defined in data-tab to the master-data band using PascalScript code. Something like this:

procedure frxReport1OnStartReport(Sender: TfrxComponent);
begin
  MasterData1.Dataset := <ADOQuery1."ADOQuery1">;      
end;