Drupal expect not null value for pages field. Corrected code

$query6 = db_query("INSERT INTO {blocks} (module, delta, theme, status, weight, region, custom, throttle, visibility, pages)
              VALUES ('%s', '%s', '%s', %d, %d, '%s', %d, %d, %d, '%s')", 
              $this_module, $block_data->delta, $block_data->theme, $block_data->status, $block_data->weight, $block_data->region, $block_data->custom, $block_data->throttle, $block_data->visibility, $block_data->pages);