DECLARE 
    filename VARCHAR2(200); 
BEGIN 
    filename := 'C:\NEW\IMAGE_FILE\' ||:block_name.item_code ||'.jpeg'; 

    Read_image_file(filename, 'JPEG', 'OPTIONS_IMAGE'); 

    IF NOT form_success THEN 
      Read_image_file('C:\NEW\IMAGE_FILE\blank.jpg', 'JPEG', 'OPTIONS_IMAGE'); 
    END IF; 

END; 

Select St_id, St_name  from student;

function CF_1Formula return Char is
begin
  Return ('C:\'||:St_id||'.jpg');
end;

function CF_1Formula return Char is
LOC VARCHAR2(40):='C:\';
PIC VARCHAR2(500);
out_file Text_IO.File_Type;
BEGIN
  out_file :=Text_IO.Fopen(LOC||:EmployeeId||'.JPG', 'r'); -- r is read only
  PIC:=LOC||:EmployeeId||'.JPG';
  RETURN PIC;
    exception
      when others then 
     RETURN 'C:\3'||'.JPG';
     
end;