How to retrieve an InterBase Blob in Delphi using SavetoFile

There are several ways of retrieving InterBase Blob data within Delphi.
This example uses the SaveToFile method.

* Put TDatabase, TQuery, TDatasource and TDBGrid on the form.
* set the Tdatabase's fields as follow:
> Alias name to the BDE Alias.
> DatabaseName to something you wish.
> Connected to true
* Set the TQuery fields as follow:
> SQL to the sql statement to be executed, ie select * from
> DatabaseName to the same name you've named in the
previouse step.

* Set the TDatasource field DataSet to the name
of the Tquery component. Default is query1.
* Set the TDBGrid field DataSource to the name of
the TDataSource component. Defualt is Datasource1.
* Go back to TQuery component and double click.
* Right click on the blank space on the windows said
"form1.query". And choose add fields.
* Select all the fields in the list and added.
* Drop a TButton on the form.
* Double click on the Tbutton.
* Add the following lines between begin and end;

procedure TForm1.Button1Click(Sender: TObject);

Note: image is the field name defined as blob.
And c:testimage.jpg is where the location of the
image file to be created.

* Save the project/form/unit. and Run.
* Click on the Button will retrieve a blob entry and create file image.jpg.