Hi,
I'am not sure that i really understood whole problem but decided to prepare a
small usefull code sample;
Function TForm1.ReconnectIfNotConnected : Boolean; //Connection Control...
begin
Result := False;
if not (AdoConnection1.Connected) then
try
AdoConnection1.Connected := True;
Result := True;
except
Showmessage('Connection error:' + #13#13#10 + 'Connection
String : ' + AdoConnection1.ConnectionString );
end;
end;
Function TForm1.RefreshSqlResult(sql : String; aq : TAdoQuery = AdoQuery1) :
Boolean; // Querying...
begin
// using TAdoQuery whose Connection is TAdoConnection1.
// use a DataSource whose dataset is TAdoQuery1 or aq which you already
assigned.
(aq as TAdoQuery).Active := False;
(aq as TAdoQuery).Sql.text := sql;
try
(aq as TAdoQuery).Active := True;
Result := ((aq as TAdoQuery).RecordCount > 0 );
except
Showmessage('DB Error:' + #13#13#10 + 'Query : ' + sql);
end;
end;
Procedure TForm1.UsefullCode; // main functions...
var sqls , OneStringField : String; Count : integer;
begin
if ReconnectIfNotConnected then begin
sqls := 'select * from Table';
if RefreshSqlResult(sqls , AdoQuery1) then begin
{ Finding record count}
Count = AdoQuery1.RecordCount;
{or}
{Fetching dataset...}
AdoQuery1.First;
While not AdoQuery1.eof do begin
OneStringField := AdoQuery1.FieldByName('FieldName').Asstring;
AdoQuery1.Next;
end;
end else begin
Showmessage('No result found in query : ' + #13#13#10 + sqls);
end;
end;
end;
> > procedure Tform1.button1Click (Sender: Tobject);
> > Begin
> > Q1.close;
> > Q1.sql.clear;
> > Q1.sql.add(' select * from Table');
> > Q1.open;
> > Q1.RecordCount;
> > ClientDataSet1. open; //Dups Q1.Query DataSet
> > Q1.close; //Saving wear and tear on Server so running from Mem Buffer
> > ClientDataSet1. RecordCount; //1st try works properly
> > //later comes up empty even though
> > //Q1.RecordCount has increased
> >
> > //Do Things with ClientDataSet1/ /
> > ClientDataSet1. EmptyDataSet;
> > ClientDataSet1. close;
> > Form1.Button1. Click; //Repeat until the cows come home
> >
> > //Tried removing the DataSet.close and adding ClientDataSet1. refresh
> > with same empty result set after 1st pass?//
> >
> > Any suggestions on properly refreshing the ClientDataSet1?
> >
> > Thanks so much!
> > Tony
----- Original Message ----
From: Tony1L <[EMAIL PROTECTED]>
To: advanced_delphi@yahoogroups.com
Sent: Tuesday, May 29, 2007 5:01:11 PM
Subject: [advanced_delphi] Re: ClientDataSet loop not refreshing with any
records
Thanks for the reply but alas this is not entirely the solution.
I've
posted my code below. Notice the lines (ClientDataSet1. Open;
ClientDataSet1. Close) but when it loops I'm not getting refreshed data
actually no records after it reopens. Query's getting refreshed
during debug I have query.recordcount and can see the increased count
and can see that the ClientDataSet is being closed/opened but there's
some reason that it's not getting populated. Any other tips or
suggestions?
--- In advanced_delphi@ yahoogroups. com, "Vo Viet Anh"
<vietanh1969@ ...> wrote:
>
> Hi Tony,
> the orderly way to refresh a ClientDataset is to close it and open
again,
> also:
>
> ClientDataSet1. Close;
> ClientDataSet1. Open;
>
> That's all!
> Don't bore with the Query, MIDAS will do it automatically (and
correctly)
> for you.
>
> BTW: I think such technique are clearly represented in the User
Manual and
> online-help. Why not take a look?
>
> Viet Anh
>
> On Sat, 26 May 2007 04:22:57 +0700, Tony1L <[EMAIL PROTECTED]> wrote:
>
> > I have a project where I'm repeatedly calling a Button.Click event in
> > which I'm using an ADOConnection to a MSSQL Database with Query and
> > also open a ClientDataSet with corresponding DataSetProvider directed
> > to the Query. Once it goes back through the code again ClientDataSet1
> > isn't receiving any records...even through I see them by checking
> > Q1.RecordCount. On the second...third pass the ClientDataSet1
> > is set to 0? What could I add to this to properly refresh the
dataset?
> >
> > Sample Code:
> > procedure Tform1.button1Click (Sender: Tobject);
> > Begin
> > Q1.close;
> > Q1.sql.clear;
> > Q1.sql.add(' select * from Table');
> > Q1.open;
> > Q1.RecordCount;
> > ClientDataSet1. open; //Dups Q1.Query DataSet
> > Q1.close; //Saving wear and tear on Server so running from Mem Buffer
> > ClientDataSet1. RecordCount; //1st try works properly
> > //later comes up empty even though
> > //Q1.RecordCount has increased
> >
> > //Do Things with ClientDataSet1/ /
> > ClientDataSet1. EmptyDataSet;
> > ClientDataSet1. close;
> > Form1.Button1. Click; //Repeat until the cows come home
> >
> > //Tried removing the DataSet.close and adding ClientDataSet1. refresh
> > with same empty result set after 1st pass?//
> >
> > Any suggestions on properly refreshing the ClientDataSet1?
> >
> > Thanks so much!
> > Tony
> >
> >
> >
>
>
>
> --
> Using Opera's revolutionary e-mail client: http://www.opera. com/mail/
>
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