[support] Database query cache issue

[Kamal Palei]

Hi All
I am using Drupal 6.26.

I am trying to upload a file. One user can upload only one file.
After a while, if user wants to upload another file, I need to delete the
first file and upload the second file.
To delete the first file, I do a query to get the first file name, deletes
first file and uploads the second file.
After a while, if user wants to upload another file, when I do query to get
the second file name (as I want to delete the second file now), I always
get the first file name.
So I am not able to delete the second file.

Probably database cache plays a role here, how can I make sure, my query
returns the latest data present in table, query should not pick the data
from cache.

Please refer code below.

 global $user;
 $FID = -1;

 $result = db_query("SELECT fid, filepath FROM {resubmt_table} LEFT JOIN
{files} USING (fid) WHERE resubmt_table.uid = %d", $user->uid);
 $obj = db_fetch_object($result);
 if($obj)
 {
  $FID = $obj->fid;
  if($obj->filepath)
  {
   if(file_exists($obj->filepath))
   {
    drupal_set_message("File exists deleting " . $obj->filepath);
    unlink($obj->filepath);
   }
   else
   {
    drupal_set_message("File does not exists, so not able to delete, file =
" . $obj->filepath);
   }
  }
 }


Many times, I am not able to delete the file.
Please suggest how can I fix this issue.

Thanks
Kamal
NECS, Bangalore
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