Extract binary data from resource_view (/Resrouce/Contents/binary)

Question

Hi,
I've uploaded an image (png) as a resource using ftp. Now I'd like to extract the contents of the png file using the resource_view.
In my test the uploaded file was placed in /public/tmp and was named test.png.
Using the following query I tried to get the data:
SELECT extract(res,'/Resource/Contents/binary') AS content, extractValue(res,'/Resource/ContentType') AS ContentType
FROM resource_view
WHERE equals_path(res,'/public/tmp/test.png') = 1 The output was something like:
<binary xmlns="http://xmlns.oracle.com/xdb/XDBResource.xsd">89504E470D0A1A0A0000000D494844520000023E00000181080300000051984BA3000003
00504C5445000000BF000000BF00BFBF000000BFBF00BF00BFBFC0C0C0C0DCC0A4C8F0111111222222444444555555777777AAAAAADDDDDDEEEEEE00001100002200
00440000550000770000880000AA0000BB0000DD0000EE00110000220000440000550000770000880000AA0000DD0000EE0011000022000044000055000077000088...</binary>
image/pngThis looks a lot like ASCII :-) Following the XSD the binary data is hexBinary encoded.
My question is how to get the binary representation?
(oh, I'm running 11g on 64bits Windows)
Edited by: Tijink on Feb 2, 2009 3:20 AM

Answer 1

First create a function to convert the hexvalues in the string to a blob:
create or replace function myclob2blob( p_clob in clob )
return blob
is
  t_blob blob;
begin
  dbms_lob.createtemporary( t_blob, true );
  for i in 0 .. trunc( length( p_clob ) / 4000 )
  loop
    dbms_lob.append( t_blob, to_blob( hextoraw( to_char( substr( p_clob, i * 4000 + 1, 4000 ) ) ) ) );
  end loop;
  return t_blob;
end;
/And then query the binary data using this function
select extractvalue( rv.res, '/Resource/DisplayName' ) displayname
     , extractvalue( rv.res, '/Resource/ContentType' ) ContentType
     , myclob2blob( bin ) bin
from resource_view rv
   , xmltable( '/' passing extract( rv.res, '/Resource/Contents/binary' )
                columns bin clob path '/*'
where equals_path( rv.res, ''/public/tmp/test.png' ) = 1 Anton