how to using 'count'

For the future, please post a question only once at a time; there is no need to post a question in more than one forum.

Thx for your replay.. :)
finally i've got the answer.. count all comment using linq sql and c#

protected String GetCountComment(string IdTopic)
    {
        string value = String.Empty;
        DMSDataAccess db = new DMSDataAccess();
        var comment = db.DMSDataContext.Comments.Where(p => Convert.ToString(p.IdTopic) == IdTopic);

        value = Convert.ToString(comment.Count());
        return value;
    }

Sam Hobbs15y ago

Also see how to using 'count'.

Guest User15y ago

select count(*) from topic inner join comment on Comment.IdTopic = Topic.IdTopic

(that's the sql solution)