[lazarus] TDBGrid question
hernan.et at pg.com
hernan.et at pg.com
Fri May 23 02:20:55 EDT 2003
Hi Jesus,
The scrollbars work for me now just fine. Here is what I did.
I created another TIBQuery, this will just tell me how many records are returned
based on the SQL passed. I don't understand why I can't get the number of
records when using pure sql, e.g.
myIBQry.SQL.Clear;
myIBQry.SQL.Add('Select * from items');
myIBQry.Open;
myIBQry.RecordCount does not work (myIBQuery is of type TIBQuery).
my second query looks like this
myIBSecond.SQL.Clear;
myIBSecond.SQL.Add('Select count(ID) as NumOfItems from items');
myIBSecond.Open;
myTDBGrid.RowCount := IntToStr(myIBSecond.Fields[0].AsString); //note no
AsInteger I don't know why
myTDBGrid.BufferCount := myTDBGrid.RowCount; //this will update
FDataLink.BufferCount --> note my message below
myTDBGrid.ColCount := 8;// this can be determined in advanced.
About the streaming, I have the same problem before. One of the guru's around
just redeclared all properties in your final class in the published section. If
you have an archive look at TIBDatabase,TIBQuery and its decendants and compare
that with the current source code.
Regards,
Yoyong Hernan
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From: "Jesus Reyes" <jesusrmx at yahoo.com.mx> on 05/23/2003 01:43 AM GMT
"Jesus Reyes" To: lazarus at miraclec.com
<jesusrmx at yahoo.com.mx> Cc: (bcc: Yoyong Hernan-ET/PGI)
Subject: RE: [lazarus] TDBGrid question
05/23/2003 09:43 AM
Please respond to
lazarus at miraclec.com
I thought that I corrected those details, later I will try to verify this,
thanks.
Meanwhile feel free to do any changes later if you like we can insert them,
I wanted to get the scrollbars working but for the moment I cant, I tried to
do a package with the new package system and I detected some painting
problems while in form designing, I packaged a TMySQLDataset component and
for the first time a see the grid filling a design time !. Unfortunatelly
TDataSet derivatives seems to have problems at the form streaming time :(.
I'm not in the office so I cant post the backtraces but it seem its a RTTI
issue.
regards.
Jesus Reyes A.
----- Original Message -----
From: <hernan.et at pg.com>
To: <lazarus at miraclec.com>
Sent: Thursday, May 22, 2003 5:14 PM
Subject: Re: [lazarus] TDBGrid question
> Hi Jesus,
>
> Here is what I have done inorder for me to work with TDBGrid.
>
> I added/created a property named BufferCount in TDBGrid class
>
> property BufferCount : Integer Read FBufferCount Write SetBufferCount;
>
> procedure TCustomDBGrid.SetBufferCount(const Count : Integer);
> begin
> FBufferCount := count;
> if Count > RowCount then
> FDataLink.BufferCount := count
> else
> FDataLink.BufferCount := RowCount;
> end;
>
> I changed UpdateBufferCount to
>
> procedure TCustomDBGrid.UpdateBufferCount;
> begin
> if BufferCount <= RowCount then
> FDataLink.BufferCount := RowCount + 1
> else
> FDataLink.BufferCount := BufferCount;//buffer count of this
class
>
> end;
>
> The reason I did this was that I discovered when I set
FDataLink.BufferCount to more than my table's number of records, I can
scroll the TDBGrid fine.
>
> Hope you can validate if this work around is correct.
>
> Regards,
>
> Yoyong Hernan
>
>
>
>
> Internet Mail Message
> Received from host:
> svcr-216-37-230-2.dsl.svcr.epix.net
> [216.37.230.2]
>
>
>
> From: Jesus Reyes <jesusrmx at yahoo.com.mx> on 05/19/2003 05:19 PM GMT
>
> Jesus Reyes To: lazarus at miraclec.com
> <jesusrmx at yahoo.com.mx> Cc: (bcc: Yoyong Hernan-ET/PGI)
> Subject: Re: [lazarus] TDBGrid question
>
> 05/20/2003 01:19 AM
> Please respond to
> lazarus at miraclec.com
>
>
>
>
>
>
> --- Michael Van Canneyt <michael.vancanneyt at wisa.be> escribió: >
> >
> > On Mon, 19 May 2003 hernan.et at pg.com wrote:
> >
> > >
> > >
> > > Hi Jesus,
> > >
> > > I have tried using TDBGrid and it work quite well. But I noticed
> > that I cannot
> > > scroll backward when my table contains more than 10, (my table
> > contains 56
> > > rows). I have tried to track it down and it seems that the
> > problem is somewhere
> > > in TDataset or its parent(s). Can someone have a look on this?
> >
> > I've had this issue in the past, and I suspect has something to do
> > with the buffer
> > scrolling. I have not yet been able to pinpoint the exact error,
> > however.
> >
> > The procedure you want is in dataset.inc, line 1634
> >
> > Procedure TDataset.ShiftBuffers (Offset, Distance : longint);
> >
> > Subprocedure 'shiftbuffersdown'.
> >
> > I currently do not have enough time to look at it, but if someone
> > else
> > has, the above info may help to pinpoint the exact problem.
> >
> > Michael.
> >
>
>
> Sorry, I missed the original message from Yoyong. Still I can't
> reproduce the problem, I have a dataset with hundreds of rows and i
> can go forward/backward without problem. Can you give more details
> about dbgrid geometry/dataset derivative, a backtrace?
>
> Thanks.
>
> Jesus Reyes
>
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