Database Logon Dialog appears when previewing

rbuser

Good Evening All:

I have run into a problem that I cna't seem to get around.

I created a stand alone app to enable testing of the creation, import and
export of report templates for my client.

Everything went well and I began the process of incorporating the end-user
components into an existing application module. (copied the end-user
queries, datasources, pipelines, the report component, designer, explorer
and the data dictionary from the standalone app and pasted into existing
datamodule).

All the copied components were pointed to the appropriate session etc. and I
am able to compile and run the application and execute the explorer
component. All the templates are visible.

The problem arises when I try to preview a report.

A database logon dialog appears, asking for my username, password and the
database.

The database field displays the name of the session component from the test
application.

If I ignore the dialog, I get a 'Cannot Generate Report. Not Logged In'
error message.

If I enter my username and password, but leave the old session name or even
substitute the new session name, I get a TNS error that tells me I am trying
to use a connect string that Oracle does not recognize.

If I enter an actual database name, the logon dialog will disappear, but
will reappear for each datasource created on the data tab.

The report will eventually run in this manner and display the expected data.

Any ideas?

TIA

--
Geoff Dunmore
Rylex Software Systems
Box 346
Ruthven ON N0P 2G0
rylex@cogeco.ca

nardmoseley

When you create a new Query DataView using DADE, the DatabaseName is saved
as part of the definition. When the report loads, it tries to resolve the
database name object reference.

Please the following article for details...

-------------------------------------------------
Tech Tip: 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;


4. Below is a tech tip for extracting the SQL object
from a report. TdaSQL is a class defined in daQClass.pas.

-------------------------------------------------
Tech Tip: 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;





--
Tech Support mailto:support@digital-metaphors.com
Digital Metaphors http://www.digital-metaphors.com


--
Nard Moseley
Digital Metaphors Corporation
http://www.digital-metaphors.com

rbuser

Nard:

Thank-you for your quick response.

Your solution works wonderfully for simple reports, but I continue to have
problems with more complex reports that have linked/multiple dataviews.

Does the database name need to be replaced for each seperate dataview?

Would I be correct in assuming that one would have create a separate
procedure that returned the count of dataview and then use this result to
iterate through the dataviews array and apply the database update to each?

Thanks in advance.

--
Geoff Dunmore
Rylex Software Systems
Box 346
Ruthven ON N0P 2G0
rylex@cogeco.ca

nardmoseley

You are correct, you need to update the database name for each dataview by
iterating thru the DataModule.DataViews[] array.

example:

for liIndex := 0 to myDataModule.DataViewCount-1 do
begin
lDataView := myDataModule.DataViews[liIndex];

if lDataView is TdaQueryDataView then
{call routine to extract the SQL object and update the name}

end;




--
Nard Moseley
Digital Metaphors
http://www.digital-metaphors.com

rbuser

Thank-you!

Works like a charm.

--
Geoff Dunmore
Rylex Software Systems
Box 346
Ruthven ON N0P 2G0
rylex@cogeco.ca