# $blob_a_data is a GIF, or other binary data

      $db->do("INSERT INTO blob_table (blob_a)
               VALUES (?)", {}, $blob_a_data);

      # Later on...

      my ($blob_a_fromdb) = 
        $db->selectrow_array("SELECT blob_a
                              FROM blob_table");

      # $blob_a_fromdb and $blob_a_data should be the same.