[development] Convert query to COUNT query

I'm havng trouble getting my head around converting this to a count query for doing a pager_query. SELECT c.name, c.mail, COUNT(*) AS num, pv.value AS usertype, td.name AS role  FROM {comments} c  INNER JOIN {node} n ON n.nid=c.nid  INNER JOIN {term_node} tn ON tn.nid=n.nid AND tn.vid=n.vid  INNER JOIN {term_data} td ON td.tid=tn.tid AND td.vid = 2  LEFT JOIN {profile_values} pv ON pv.uid=c.uid AND pv.fid = 13  WHERE c.mail <> ''  GROUP BY role, c.mail ORDER BY num DESC   I know the pv.value (usertype, LEFT JOIN profile_values) is not needed. But a user (c.mail) will end up in multiple roles (td,name, this is not the same as a Drupal role), so DISTINCT is my real downfall here. Nancy