Update Database Name

How to modify the DatabaseName stored with a DADE Query

Currently when DADE is used to create dataviews, the DatabaseName is stored as part of the query definition. (This is consistent with Delphi's approach to specifying a database connection for a Query object).

In some cases, you may decide that the DatabaseName needs to be modified at a later date.

We recommend that the DatabaseName refer to a TDatabase connection component or to an Alias to provide flexibility for changing the connection parameters.

A second way to handle this issue is to implement some code that specifies a DatabaseName whenever a template is loaded. This can be accomplished by using the Report.Template.OnLoadEnd event.

1. Declare an event-handler procedure in the private section of your form declaration.
   

   type
      myForm = class(TForm)
        private
          procedure ReportTemplateLoadEndEvent(Sender: TObject);
        public
      end;

2. Use the FormCreate event to assign the event-handler to the event property.
   

   procedure myForm.FormCreate(Sender: TObject)
   begin
     Report1.Template.OnLoadEnd := ReportTemplateLoadEndEvent;
   
   end;

3. Add code to the event-handler to specify the database name.

    
   procedure myForm.ReportTemplateLoadEndEvent(Sender: TObject)
   var
     lSQL: TdaSQL;
   
   begin
     if GetSQLObject(Report1, lSQL) then
       begin
         lSQL.DatabaseName := Designer.DataSettings.DatabaseName;
         SetSQLObject(Report, lSQL);
         lSQL.Free;
   
       end;
   
   end;

   
   Below is a tech tip for extracting the SQL object from a report. TdaSQL is a class defined in daSQL.pas.
   The example code extracts only DataViews[0]. If the report contains multiple dataviews, you will need to iterate thru all of the entries in the DataViews[] array.
   

   How to access the SQL object associated with a Report created using DADE

   uses
     daDatMod;
   
   function GetSQLObject(aReport: TppReport; var aSQL: TdaSQL): Boolean;
   var
     lDataModule: TdaDataModule;
     lDataView: TdaDataView;
   begin
   
     aSQL := TdaSQL.Create(nil);
   
     {get the datamodule}
     lDataModule := daGetDataModule(aReport);
   
     if (lDataModule <> nil) then
       begin
         lDataView := lDataModule.DataViews[0];
   
         if (lDataView <> nil) and (lDataView is TdaQueryDataView) then
           aSQL.Assign(TdaQueryDataView(lDataView).SQL);
   
       end;
   
     Result := (aSQL <> nil);
   
   end;
   
   procedure SetSQLObject(aReport: TppReport; aSQL: TdaSQL);
   var
     lDataModule: TdaDataModule;
     lDataView: TdaDataView;
   begin
   
     {get the datamodule}
     lDataModule := daGetDataModule(aReport);
   
     if (lDataModule <> nil) then
       begin
         lDataView := lDataModule.DataViews[0];
   
         if (lDataView <> nil) and (lDataView is TdaQueryDataView) then
           TdaQueryDataView(lDataView).SQL := aSQL;
   
       end;
   
   end;