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TZConection pbm
Posted: 07.06.2008, 22:30
by akli_agha
Hi there,
I tried to export some data from one table of a DB to another table of another DB. The first exists yet but the second is created at run time.
I'm using one TAQuery to fill my table and a TZReadOnlyQuery to read the existing table.
Process : Create DB and Table to fill, open ZReadOnlyQuery, execute SQL statement of the ZQuery(Insert into ....) and Commit each 500 records.
The process runs correctly till the opening procedure of the TZReadOnlyQuery (which is connected correctly to the 1st DB and its SQL text is so simple, just a select on 4 fields), then program stops whith this message : Invalid Database Handle.
An idea ??
Thanks.
Posted: 08.06.2008, 19:47
by mdaems
No idea, but some information may be helpful. eg. which database are you using.
If the project and data can be packaged easily : drop some copy here or in the bug tracker if you think it's a bug.
Mark
Posted: 08.06.2008, 22:53
by akli_agha
Hi Mark,
I'm using FB 2.0 with Zeos 662. Here is the portion of the code I used :
Code: Select all
procedure TfrmMain.mnFraisClick(Sender: TObject);
var
myConnection : TZConnection;
myQuery : TZQuery;
qStudent : TZReadOnlyQuery;
sYear, dbName, expDir : String;
n : integer;
begin
expDir := '';
if SelectDirectory('Choisir l''endroit où exporter', expDir, expDir) then begin
expDir := IncludeTrailingBackSlash(expDir);
sYear := IntToStr(Year(Date));
dbName := expDir + 'FRAIS_BAC_' + sYear + '.FDB';
MyUserId := 'SYSDBA';
myPw := 'masterkey';
Application.ProcessMessages;
if not FileExists(dbName) then begin
myConnection := TZConnection.Create(nil);
try
with myConnection do begin
User:= MyUserId;
Password:= myPw;
Database:= dbName;
Protocol := 'firebirdd-2.0';
Properties.Add ('CreateNewDatabase=CREATE DATABASE ' +
QuotedStr(dbName) + ' USER ' + QuotedStr(MyUserId) +
' PASSWORD ' + QuotedStr(myPW) + ' PAGE_SIZE 4096');
AutoCommit := False;
Connected := True;
myQuery := TZQuery.Create(nil);
try
myQuery.Connection := myConnection;
myQuery.SQL.Clear;
myQuery.SQL.Add('CREATE TABLE BAC ('+
' ID_BAC SMALLINT,'+
' CODEBAC VARCHAR(20),'+
' NOM VARCHAR(60),'+
' PRENOM VARCHAR(60),'+
' DN CHAR(10),'+
' DATE_J DATE,'+
' MONTANT DECIMAL(10,2))');
myQuery.ExecSQL;
myQuery.SQL.Clear;
myQuery.SQL.Add('INSERT INTO BAC ('+
' ID_BAC, CODEBAC, NOM, PRENOM, DN) '+
'VALUES(:ID_BAC, :CODEBAC, :NOM, :PRENOM, :DN)');
qStudent := TZReadOnlyQuery.Create(Self);
//Existing DB in the Data Module
qStudent.Connection := DM.SIW;
qStudent.SQL.Clear;
qStudent.SQL.Add('SELECT CODEBAC, NOM, PRENOM, DN '+
'FROM STUDENT');
qStudent.Open;
frmProgress := TfrmProgress.Create(Self);
frmProgress.myGauge.MinValue := 0;
frmProgress.myGauge.Progress := 0;
frmProgress.lblProgress.Caption := 'Exportation en cours ...';
frmProgress.myGauge.MaxValue := qStudent.RecordCount;
frmProgress.Show;
qStudent.First;
n := 1;
While not qStudent.eof do begin
myQuery.ParamByName('ID_BAC').AsInteger := n;
myQuery.ParamByName('CODEBAC').AsString :=
Copy(qStudent.FieldByName('CODEBAC').AsString, 1, 20);
myQuery.ParamByName('NOM').AsString :=
Copy(qStudent.FieldByName('NOM').AsString, 1, 60);
myQuery.ParamByName('PRENOM').AsString :=
Copy(qStudent.FieldByName('PRENOM').AsString, 1, 60);
myQuery.ParamByName('DN').AsString :=
Copy(qStudent.FieldByName('DN').AsString, 1, 10);
myQuery.ExecSQL;
Inc(n);
if (nSize mod 500) = 0 then begin
Commit;
Application.ProcessMessages;
end;
qStudent.Next;
frmProgress.myGauge.Progress :=
frmProgress.myGauge.Progress + 1;
end;
qStudent.Close;
Commit;
Connected := False;
finally
FreeAndNil(frmProgress);
FreeAndNil(qStudent);
FreeAndNil(myQuery);
end;
end;
finally
FreeAndNil(myConnection);
end;
Application.ProcessMessages;
end;
end;
Application.ProcessMessages;
end;