i'm working on a site that has downloads.i have added a comment mod to the script.
i have a comments table.how can i add # of comments to the files table?

There are two reasonable approaches.
1. Every time you show a single file or a listing of files "select count(*) from comments where file_id = ... " for single file or "... where file_id in (...)" for a listing of files with further numbers assignment within php.
2. Every time a user adds a comment "update files set comments_count = comments_count + 1 wher file_id = ...", but first you will have to count numver of comments that already exists.
The second way is less resource-consuming, but needs more attention while being implemented not to lose some comments if done unproperly.

thanks for replying,but i dont understand what you said.
my knowledge of sql is somewhat limited.

Did you do all the coding yourself?

no i downloaded it,(pafiledb) and i added the comment mod which needed a sql query to add the comment table.

Dammit man, I cannot tell you where to add what exactly. You need some basic knowledge of php and mysql to do what you want, because your problem is rather simple.

sorry now i know what you were saying.
not thinking clear latly.
1.doesn't sound good.
2.there is no comment count in files,hense the reason for the topic.
the php i might be able to do or find out how.
i know some php,but it is mainly editing or copying from other scripts.