Here is a part of code from comments module in the function function comment_render
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if ($cid) {
// Single comment view.
$result = db_query('SELECT c.cid, c.pid, c.nid, c.subject, c.comment, c.format, c.timestamp, c.name, c.mail, c.homepage, u.uid, u.name AS registered_name, u.picture, u.data, c.score, c.users FROM {comments} c INNER JOIN {users} u ON c.uid = u.uid WHERE c.cid = %d AND c.status = %d GROUP BY c.cid, c.pid, c.nid, c.subject, c.comment, c.format, c.timestamp, c.name, c.mail, u.picture, c.homepage, u.uid, u.name, u.picture, u.data, c.score, c.users', $cid, COMMENT_PUBLISHED);
if ($comment = db_fetch_object($result)) {
$comment->name = $comment->uid ? $comment->registered_name : $comment->name;
$output .= theme('comment_view', $comment, module_invoke_all('link', 'comment', $comment, 1));
}
}
else {
// Multiple comment view
$query .= "SELECT c.cid as cid, c.pid, c.nid, c.subject, c.comment, c.format, c.timestamp, c.name, c.mail, c.homepage, u.uid, u.name AS registered_name, u.picture, u.data, c.score, c.users, c.thread FROM {comments} c INNER JOIN {users} u ON c.uid = u.uid WHERE c.nid = %d AND c.status = %d";
$query .= ' GROUP BY c.cid, c.pid, c.nid, c.subject, c.comment, c.format, c.timestamp, c.name, c.mail, u.picture, c.homepage, u.uid, u.name, u.picture, u.data, c.score, c.users, c.thread';