how to load os file into blob field ?

If you want to to load a file (i.e. text file, image file, pdf file etc.) into
a blob field, then follow the following procedure.

1. create a database directory :
create or replace database directory image_test_dir
as 'd:\db_dir\'

2. Use dbms_Lob package to load os file into blob;

   declare
    
        v_file_loc      bfile;
        
        v_Image_size    integer;
        
        v_img           blob;
    
    begin
        
        --v_file_loc      := bfilename('IMAGE_TEST_DIR', 'testRpt.pdf');
        v_file_loc      := bfilename('IMAGE_TEST_DIR', 'front.tif');
        
        v_image_size    := DBMS_LOB.GETLENGTH(v_file_Loc);
        
        dbms_output.put_line(v_image_size);
        
        insert into image_upload(id, img)
        values (1, empty_blob()) returning img into v_img;
        
        dbms_Lob.open(v_file_Loc, DBMS_LOB.FILE_READONLY );        
        
        DBMS_LOB.LOADFROMFILE( v_img, 
         v_file_loc,
         v_image_size   );
         
         DBMS_LOB.CLOSE(v_file_Loc);
        
        commit;
        
    
    exception
        when others then dbms_output.put_line('Exception :  ' || sqlerrm);    
        
    end;