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Article #25238: How to retrieve an InterBase Blob in Delphi using SavetoFile?

Problem:
This is an  example of how to retrieve an InterBase Blob in Delphi.

Note:
While this example was designed specifically for Interbase, it can easily be made to apply to any database.

Solution:
IB V4.x
Delphi 3.0


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
	   table1
	>  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);
begin
query1image.savetofile('c:testimage.jpg');
end;



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.

 


Last Modified: 02-OCT-00