Why RB allways open dataviews

rbuser

RB 10.06, BDS2006, Interbase, IBX

I have a Report designed at runtime, with a query assigned by SQL.Text
directly. Well, i have created and event handler, in the application
ppReport for the event BeforeOpenDataPipelines, to assign parameters
before open que query.

Well, i'm doing a trace, and allways before the call to the event, RB
opens all the querys, then i edit the parameters, assign them, and RB
opens the query again.

How can i prevent for not open the querys, because may be a waste of
time opening heavy querys for doing nothing, because the querys has no
parameters.

This is a trace of what RB does before call the event
BeforeOpenDataPipelines, and as you can see all the querys are opened.

14/08/2007 9:55:08
[Application: Test 6.0]
IBTransaction: [Commit (Hard commit)]
14/08/2007 9:55:08
[Application: Test 6.0]
: [Prepare] select *
from peticion
where Fecha >= :Fecha_Consulta

Plan: PLAN (PETICION INDEX (PETICION_IDX0))
14/08/2007 9:55:08
[Application: Test 6.0]
: [Execute] select *
from peticion
where Fecha >= :Fecha_Consulta

FECHA_CONSULTA =
14/08/2007 9:55:08
[Application: Test 6.0]
: [Fetch] select *
from peticion
where Fecha >= :Fecha_Consulta

SEOFReached
14/08/2007 9:55:08
[Application: Test 6.0]
: [Prepare] select *
from peticion
where Fecha >= :Fecha_Consulta

Plan: PLAN (PETICION INDEX (PETICION_IDX0))



--

nardmoseley

That information is not detailed enough to determine why the dataviews are
opened.

Try adding Delphi\Lib\Debug and RBuilder\Source to your Delphi library path.
Then trace in the debugger and put some stops daIBExpress or ppDBPipeline at
the point where the datapipeline is opened or the query is set to active.
When the debugger stops, then examine the call stack.


--
Nard Moseley
Digital Metaphors
www.digital-metaphors.com

rbuser

Nard Moseley (Digital Metaphors) wrote:


Ok, i have done it and i see where is the problem.

Before print the report, i want to get the parameters of the query to
show the end user a form requesting the parameters values, then i get
the sqlTEXT

sSQL := TdaIBXQueryDataView(TppDBPipeline( ppInforme.DataPipeline
).DataView).SQL.SQLText.Text;

when i call this code is executed

function TdaSQL.GetSQLText: TStrings;
begin

Result := FSQLText;

if (csWriting in ComponentState) or (csReading in ComponentState) or
(csLoading in ComponentState) then Exit;

if (FSQLOutOfSync) then
if FEditSQLAsText then
CreateFieldsFromSQL <=============================

call to

TdaSQL.CreateFieldsFromSQL;

calls to

TdaSQL.GetFieldsForSQL(aSQL: TStrings; aList: TList): Boolean;

and calls to

procedure TdaIBXDataSet.GetFieldsForSQL(aList: TList; aSQL: TStrings);
var
lQuery: TIBQuery;
lQueryField: TField;
lField: TppField;
liIndex: Integer;
begin
aList.Clear;

{create a temporary IB query}
lQuery := TIBQuery.Create(Self);

try

{assign databae and SQL properties}
lQuery.Database := TIBDatabase(Database);
lQuery.SQL := aSQL;

{set query to active}
lQuery.Active := True;

{create a TppField object for each field in the query}
for liIndex := 0 to lQuery.FieldCount - 1 do
begin
lQueryField := lQuery.Fields[liIndex];

lField := TppField.Create(nil);

lField.FieldName := lQueryField.FieldName;
lField.FieldAlias := lQueryField.DisplayLabel;
lField.FieldLength := lQueryField.Size;
lField.DataType := ppConvertFieldType(lQueryField.DataType);
lField.DisplayWidth := lQueryField.DisplayWidth;

aList.Add(lField);
end;

finally
lQuery.Free;

end;

end; {procedure, GetFieldsForSQL}

this method, creates a copy of the query, open it and read all fields,
but i only have tried to get the sqlText, not opening the dataset and
do all process.

Because is a copy the beforeopendatapipelines event is not fired.

Is there anyway to recover the SQL text without having to do this heavy
process.



--

nardmoseley

- Open daSQL.pas and find the method, TdaSQL.Loaded

- Add the following code to the bottom of the TdaSQL.Loaded method...

if FEditSQLAsText then
FSQLOutOfSync := False;

- Test and post a message here with the results. With the above code in
place, when the DataView loads, it will initializes itself such that the
CreateFieldsFromSQL code will not be fired.


--
Nard Moseley
Digital Metaphors
www.digital-metaphors.com

rbuser

Nard Moseley (Digital Metaphors) wrote:


The same problem, because after that event, FSQLOutOfSync is returned
to true in the event

TdaSQL.SetSession(aSession: TdaSession);

that is called from TdaQueryDataView.Loaded;

and anyway TdaQueryDataView.Loaded, sets FSQLOutOfSync to true again.

--

nardmoseley

The TdaQueryDataView has an FSQLOutOfSync, but that is not related to
TdaSQL's FSQLOutOfSync. Two different classes.

The SetSession, calls Modification. You could try modifying the Modification
method like this..

if not FEditSQLAsText then
FSQLOutOfSync := True;

I don't know if that will work or not. I reviewd the code more and overall,
it looks like the TdaSQL class is trying to make sure that it knows when to
regenerate field info and so there are many places it can set SQLOutOfSync
to true.

--
Nard Moseley
Digital Metaphors
www.digital-metaphors.com