problem with TBlob*

[banita]

postgresql 8.4, unidac 2.70.0.9, c++builder 2007

I try add bitmap files into foto field. I use TUniSQL.
Under OnClick event I write:

Code: Select all

	unsql1->SQL->Clear();
	unsql1->SQL->Add("INSERT INTO t1(foto) VALUES(:P)");
	TBlob* blob = new TBlob(false);
	blob->LoadFromFile("E:\b.bmp");
	unsql1->ParamByName("P")->AsBlobRef = blob;
	unsql1->Execute();
	delete blob;

When I press button the bitmap is added to table t1 but when I close application I get error:
"invalid pointer operation"

When I comment delete blob; everythink works fine.
Whot I do wrong?

I think this is a reason:
unsql1->ParamByName("P")->AsBlobRef = blob;
..
delete blob;
but how I can delete blob object?

sory for my english

[banita]

I try do this with firebird:

Code: Select all

	unsql1->SQL->Clear();
	unsql1->SQL->Add("INSERT INTO table04 VALUES(GEN_ID(GEN_TABLE04_ID,1),:P)");
	TBlob* b = new TBlob(false);
	b->LoadFromFile("E:\b.bmp");
	unsql1->ParamByName("P")->AsBlobRef = b;
	unsql1->Execute();

	delete b;

and here: unsql1->Execute(); I get error
"acces violation... in modeule dac105.bpl"

when I do this like that:

Code: Select all

	unsql1->SQL->Clear();
	unsql1->SQL->Add("INSERT INTO table04 VALUES(GEN_ID(GEN_TABLE04_ID,1),:P)");
	unsql1->ParamByName("P")->AsBlobRef->LoadFromFile("E:\b.bmp");
	unsql1->Execute();

all works fine. why?

[eduardosic]

I try do this with firebird:

Code: Select all

	unsql1->SQL->Clear();
	unsql1->SQL->Add("INSERT INTO table04 VALUES(GEN_ID(GEN_TABLE04_ID,1),:P)");
	TBlob* b = new TBlob(false);
	b->LoadFromFile("E:\b.bmp");
	unsql1->ParamByName("P")->AsBlobRef = b;
	unsql1->Execute();

	delete b;

and here: unsql1->Execute(); I get error
"acces violation... in modeule dac105.bpl"

when I do this like that:

Code: Select all

	unsql1->SQL->Clear();
	unsql1->SQL->Add("INSERT INTO table04 VALUES(GEN_ID(GEN_TABLE04_ID,1),:P)");
	unsql1->ParamByName("P")->AsBlobRef->LoadFromFile("E:\b.bmp");
	unsql1->Execute();

all works fine. why?

In Delphi i make this..

Code: Select all

	
 unsql1.SQL.Clear;
 unsql1.SQL.Add( 'INSERT INTO table04 VALUES(GEN_ID(GEN_TABLE04_ID,1),:P)');
 
TBlobField(unsql1.ParamByName( 'P')).LoadFromFile( 'E:\b.bmp', ftBlob );
unsql1.Execute;

work's fine

[banita]

Code: Select all

	unsql1->SQL->Clear();
	unsql1->SQL->Add("INSERT INTO t1(foto) VALUES(:P)");
	TBlob* blob = new TBlob(false);
	blob->LoadFromFile("E:\b.bmp");
	unsql1->ParamByName("P")->AsBlobRef = blob;
	unsql1->Execute();
	delete blob;

When I write before 'delete blob' this code:
unsql1->Params->Clear();
then all works fine but it is strange for me.

[Plash]

You should not delete a TBlob object because the parameter has a reference to it. Instead call the Release or Free method. TBlob has the reference counter. The Release method decrements this counter. UniDAC will automatically delete Blob when the reference count is zero.

[banita]

Thanks!
I think there are two ways.

first:

Code: Select all

	TUniQuery* q = new TUniQuery(0);
	q->Connection = con1;

	q->SQL->Text = "INSERT INTO t1(foto) VALUES(:P)";
	TBlob* param = new TBlob(false);
	param->LoadFromFile("E:\b.bmp");
	q->ParamByName("P")->AsBlobRef = param;
	q->Execute();
	q->Params->Clear(); // clear params

	delete param; // and now can delete
	delete q; 

second:

Code: Select all

	TUniQuery* q = new TUniQuery(0);
	q->Connection = con1;

	q->SQL->Text = "INSERT INTO t1(foto) VALUES(:P)";
	TBlob* param = new TBlob(false);
	param->LoadFromFile("E:\b.bmp");
	q->ParamByName("P")->AsBlobRef = param;
	q->Execute();

	param->Release(); // release but dont delete

	delete q;