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"UniQuery1.UpdateTransaction" How do I use?
Posted: Wed 19 Aug 2015 23:58
by gn7soft
Hello,
I'm using UniDac6.0.2(Professional) for Firebird2.1
To commit my operations manually, I set the AutoCommit property of TUniQuery to False.
Also, to avoid the dataset is closed when commit or rollback, I used different transactions for connection and dataset.
But, eventhough I don't use different transactions for reading and modifying data, below code works good.
When do I use Uniquery1.UpdateTransaction?
Also, How do I use Uniquery1.UpdateTransaction?
Code: Select all
procedure TForm1.Button1Click(Sender: TObject);
begin
DM.UniConnection1.AutoCommit:=true; //DM: DataModule
DM.UniConnection1.DefaultTransaction := UniTransaction1;
UniQuery1.Transaction := UniTransaction2;
UniQuery1.SpecificOptions.Values['AutoCommit'] := 'False';
//Reading Data
With UniQuery1 Do
Begin
Close;
Sql.Clear;
SQL.Text:='Select * From Car';
Open;
end;
//Modifying data
If DM.UniConnection1.InTransaction=False Then DM.UniConnection1.StartTransaction;
Try
With UniQuery1 Do
Begin
Append;
FieldByName('CARNAME').AsString:=Trim(EdCarName.Text);
FieldByName('ADDR').AsString:=Trim(EdAddr.Text);
FieldByName('TEL').AsString:=Trim(EdTel.Text);
Post;
DM.UniConnection1.Commit;
End;
Except
Dm.UniConnection1.Rollback;
UniQuery1.CanCel;
End;
end;
Regards,
Peace
Re: "UniQuery1.UpdateTransaction" How do I use?
Posted: Thu 20 Aug 2015 09:10
by ViktorV
The similar question has already been discussed on our forum. Follow the link
http://forums.devart.com/viewtopic.php? ... ion#p83624 for details.
If any questions remain after reading the blog, please contact us again.
Re: "UniQuery1.UpdateTransaction" How do I use?
Posted: Thu 20 Aug 2015 17:06
by gn7soft
Thanks for your reply. I question once more.
I know that UniQuery1.UpdateTransaction is used for modifying data.
But, eventhough I don't use UniQuery1.UpdateTransaction for modifying data as below code, the below code works good. (that is, UniQuery1.UpdataTransaction property is empty but below code works good.)
I don't know when to use the UniQuery1.UpdateTransaction.
If possible, for my understand, please insert UniQuery1.UpdateTransaction in below sample code.
Code: Select all
procedure TForm1.Button1Click(Sender: TObject);
begin
DM.UniConnection1.AutoCommit:=true; //DM: DataModule
DM.UniConnection1.DefaultTransaction := UniTransaction1;
UniQuery1.Transaction := UniTransaction2;
UniQuery1.SpecificOptions.Values['AutoCommit'] := 'False';
//Reading Data
With UniQuery1 Do
Begin
Close;
Sql.Clear;
SQL.Text:='Select * From Car';
Open;
end;
//Modifying data
If DM.UniConnection1.InTransaction=False Then DM.UniConnection1.StartTransaction;
Try
With UniQuery1 Do
Begin
Append;
FieldByName('CARNAME').AsString:=Trim(EdCarName.Text);
FieldByName('ADDR').AsString:=Trim(EdAddr.Text);
FieldByName('TEL').AsString:=Trim(EdTel.Text);
Post;
DM.UniConnection1.Commit;
End;
Except
Dm.UniConnection1.Rollback;
UniQuery1.CanCel;
End;
end;
Regards,
Peace
Re: "UniQuery1.UpdateTransaction" How do I use?
Posted: Fri 21 Aug 2015 08:25
by ViktorV
Below is your modified sample using UpdateTransaction:
Code: Select all
procedure TForm1.Button1Click(Sender: TObject);
begin
DM.UniConnection1.AutoCommit:=True; //DM: DataModule
DM.UniConnection1.DefaultTransaction := UniTransaction1;
UniQuery1.UpdateTransaction := UniTransaction2;
UniQuery1.SpecificOptions.Values['AutoCommit'] := 'False';
//Reading Data
With UniQuery1 do begin
Close;
Sql.Clear;
SQL.Text:='Select * From Car';
Open;
end;
//Modifying data
if UniQuery1.UpdateTransaction.Active = False then
UniQuery1.UpdateTransaction.StartTransaction;
Try
With UniQuery1 do Begin
Append;
FieldByName('CARNAME').AsString:=Trim(EdCarName.Text);
FieldByName('ADDR').AsString:=Trim(EdAddr.Text);
FieldByName('TEL').AsString:=Trim(EdTel.Text);
Post;
UniQuery1.UpdateTransaction.Commit;
end;
except
UniQuery1.UpdateTransaction.Rollback;
UniQuery1.Cancel;
end;
end;
Re: "UniQuery1.UpdateTransaction" How do I use?
Posted: Fri 21 Aug 2015 13:46
by gn7soft
Thanks. I understood that I should be using different transactions for connections and datasets.
(also, for reading and modifying data)
I have two questions to ask you.
1) I would like to insert property of UniQuery1.Transaction in upper code.
Please see below. Is this code right?
DM.UniConnection1.DefaultTransaction := UniTransaction1;
UniQuery1.UpdateTransaction := UniTransaction2;
UniQuery1.Transaction:=UniTransaction3;
2) Eventhough UniQuery1.UpdateTransaction property is empty, below code for reading and modifying data works good. Also, a dataset(UniQuery1) is not closed. Could you tell me the reason?
Code: Select all
DM.UniConnection1.AutoCommit:=true; //DM: DataModule
DM.UniConnection1.DefaultTransaction := UniTransaction1;
UniQuery1.Transaction := UniTransaction2;
UniQuery1.SpecificOptions.Values['AutoCommit'] := 'False';
//Reading Data
With UniQuery1 Do
Begin
Close;
Sql.Clear;
SQL.Text:='Select * From Car';
Open;
end;
//Modifying data
If DM.UniConnection1.InTransaction=False Then DM.UniConnection1.StartTransaction;
Try
With UniQuery1 Do
Begin
Append;
FieldByName('CARNAME').AsString:=Trim(EdCarName.Text);
FieldByName('ADDR').AsString:=Trim(EdAddr.Text);
FieldByName('TEL').AsString:=Trim(EdTel.Text);
Post;
DM.UniConnection1.Commit;
End;
Except
Dm.UniConnection1.Rollback;
UniQuery1.CanCel;
End;
Regards,
Peace
Re: "UniQuery1.UpdateTransaction" How do I use?
Posted: Tue 25 Aug 2015 11:15
by ViktorV
1. The code you have provided with using UniQuery1.Transaction is correct.
2. If the TUniQuery.UpdateTransaction property is set to an empty string, then the default connection transaction is used for the data modification. For data reading, the transaction that is defined in the TUniQuery.Transaction property is used.
Re: "UniQuery1.UpdateTransaction" How do I use?
Posted: Tue 25 Aug 2015 15:39
by gn7soft
Thanks a lot for your kind help.
Regards,
Peace
Re: "UniQuery1.UpdateTransaction" How do I use?
Posted: Wed 26 Aug 2015 10:22
by ViktorV
Thank you for your interest to our products.
Feel free to contact us if you have any further questions about UniDAC.
Re: "UniQuery1.UpdateTransaction" How do I use?
Posted: Fri 28 Aug 2015 15:55
by gn7soft
Hello,
I have a problem during transaction.
On the below code, ①scope is not executed.
The error message is not appeared, but UPDATE statement is not executed.
But, it execute well on ZeosDbo.
I'm changing from ZeosDbo to UniDac6.0.2.
I have several code like ①scope for transaction in my project.
I would like to execute various querys in a transaction, under dataset(TUniquery) AutoCommit is False.
Please help me for successful execution of ①scope code.
Code: Select all
DM.UniConn.DefaultTransaction := DM.UniTransaction1; // DM:DataModule
UniQuery1.Transaction := DM.UniTransaction2; // a transaction for reading data
UniQuery1.UpdateTransaction := DM.UniTransaction3; // a transaction for modifying data
UniQuery1.SpecificOptions.Values['AutoCommit'] := 'False';
UniQuery3.SpecificOptions.Values['AutoCommit'] := 'False';
With UniQuery1 Do
Begin
Close;
Sql.Clear;
SQL.Text:='Select * From Car';
Open;
end;
if UniQuery1.UpdateTransaction.Active = False then UniQuery1.UpdateTransaction.StartTransaction;
Try
With UniQuery1 do begin
edit;
FieldByName('CarNo').AsString:=trim(edCarNo.Text);
FieldByName('CustCode').AsString:=trim(edCustCode.Text);
:
:
Post;
end;
with UniQuery3 Do begin //①~Start
Close;
Sql.Clear;
Sql.Text:='update CarCode Set CarNo='''+EdCarNo.Text+''''+','+
'AGuide='''+EdGuide1.Text+''''+','+
'StartDay='''+DeStartDay1.Text+''''+','+
:
:
execsql;
end; //①~End
UniQuery1.UpdateTransaction.Commit;
Except
UniQuery1.UpdateTransaction.Rollback;
End;
Regards,
Peace
Re: "UniQuery1.UpdateTransaction" How do I use?
Posted: Mon 31 Aug 2015 09:41
by ViktorV
Upon execution of the TIBCQuery.ExecSQL method, a transaction defined in the TIBCQuery.Transaction property, and not in the TIBCQuery.UpdateTransaction property, is used. To succfully execute the UPDATE query in your example, you can change it as follows:
Code: Select all
DM.UniConn.DefaultTransaction := DM.UniTransaction1; // DM:DataModule
UniQuery1.Transaction := DM.UniTransaction2; // a transaction for reading data
UniQuery1.UpdateTransaction := DM.UniTransaction3; // a transaction for modifying data
UniQuery1.SpecificOptions.Values['AutoCommit'] := 'False';
UniQuery3.SpecificOptions.Values['AutoCommit'] := 'False';
With UniQuery1 Do
Begin
Close;
Sql.Clear;
SQL.Text:='Select * From Car';
Open;
end;
if UniQuery1.UpdateTransaction.Active = False then UniQuery1.UpdateTransaction.StartTransaction;
Try
With UniQuery1 do begin
edit;
FieldByName('CarNo').AsString:=trim(edCarNo.Text);
FieldByName('CustCode').AsString:=trim(edCustCode.Text);
:
:
Post;
end;
UniQuery3.Transaction := DM.UniTransaction3;
with UniQuery3 Do begin //①~Start
Close;
Sql.Clear;
Sql.Text:='update CarCode Set CarNo='''+EdCarNo.Text+''''+','+
'AGuide='''+EdGuide1.Text+''''+','+
'StartDay='''+DeStartDay1.Text+''''+','+
:
:
execsql;
end; //①~End
UniQuery1.UpdateTransaction.Commit;
Except
UniQuery1.UpdateTransaction.Rollback;
End;
Re: "UniQuery1.UpdateTransaction" How do I use?
Posted: Mon 07 Sep 2015 02:56
by gn7soft
Thank you very much for your help.
Regards,
Peace
Re: "UniQuery1.UpdateTransaction" How do I use?
Posted: Mon 07 Sep 2015 07:03
by ViktorV
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