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Changing the Alias for a report

edited March 2005 in General
I have a situation where it was necessary to change the alias name in the
BDE pointing to an interbase database. Once I did this all of my reports
prompted me to log into the old alias. I changed the alias name witin all
of the applicable Report Builder components, but this still did not work. I
tried to change the alias name in the change data settings on the data tab,
still no luck. Finally I exported the report as an rtm and when I viewed it
in notepad it did indeed show the old alias. After changing the alias and
importing from file I was able to accomplish my original goal. My
question/comment is there must be an easier way? I feel like the change
data settings on the data tab is not working? Any suggestions/insite would
be greatly appreciated.

Thanks,

Rick

Comments

  • edited March 2005

    The recommended approach is to use a TDatabase component and configure it to
    use the Alias. Configure the Designer to use the TDatabase component. Then
    you can change the Alias without affecting the report.

    Designer ---> TDatabase ---> Alias


    Her is an article more 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 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.

    -------------------------------------------------
    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


    Best regards,

    Nard Moseley
    Digital Metaphors
    www.digital-metaphors.com
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