Question

I have a PostgreSql db that has several OID fields. The data to these fields has been inserted using the lo_import command.

But I am not able to backup the database and restore it in another server. If I try to do so, all the text entries get restored and the OID fields have a OID value, but doing an lo_export gives me an error like the File does not exist.

What is it that I am doing wrong here?

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[Edit:] Ok, I have found that the DB backup actually works but I have another unique problem. My DB server and my HTTP server are on different machines. So now my question is how do I retrieve the image in the HTTP server from the image server?

Answer 1

Here is a PHP code snippet demonstrating how to serve an image from a PostgreSQL large object to an HTTP connection:

  $db=pg_connect("dbname=mydb host=dbserver");
  pg_query("BEGIN");
  $p = pg_query("SELECT object_id, image_type FROM contents WHERE id=$some_id");
  list($oid,$type) = pg_fetch_row($p);
  $h=pg_lo_open($db, $oid, "r");
  if ($h) {
    header("Content-Type: $type");
    pg_lo_read_all($h);
    pg_lo_close($h);
  }
  pg_query("END");