Question

        int id = 1;
        string chain = "(";
        SqlDataReader dr = SqlHelper.ExecuteReader(string.Format("SELECT a.Id as x, c.Id as y From Friends b INNER JOIN Users a ON b.SenderId = a.Id INNER JOIN Users c ON b.ReceiverId = c.Id WHERE (c.Id = {0} OR a.Id = {0}) AND State = '{1}'", id, "ok"));
        if (dr.HasRows)
            while (dr.Read())
                if (id == int.Parse(dr["y"].ToString()))
                    chain += dr["x"].ToString() + ", ";
                else
                    chain += dr["y"].ToString() + ", ";
        if (chain.Length > 1)
            chain = chain.Substring(0, chain.Length - 2) + ")";
        else
            chain = "(0)";
        // Chain has for example  => (2, 3, 4, 5) => which are the Ids for Users's Friends 
        string str = "SELECT TOP 20 a.*, b.UserName as Sender, c.UserName as Receiver, b.Avatar as SenderPic";
        str += " FROM Events a INNER JOIN Users b ON a.SenderId = b.Id INNER JOIN Users c ON a.ReceiverId = c.Id ";
        str += "WHERE SenderId IN ";
        str += chain;
        str += " OR ReceiverId IN";
        str += chain;
        str += " Order BY Id desc";
        dr = SqlHelper.ExecuteReader(str);

chain considered as the user’s friends .
does any one know how to execute this query with JOINS !? Thanks a lot ..

Answer 1

SELECT distinct TOP(20) e.*, u1.UserName As Sender,
u2.UserName As Receiver, u1.Avatar AS SenderPic  
FROM Friends f INNER JOIN Users u 
ON(u.Id = f.SenderId OR u.Id = f.ReceiverId) AND State = 'ok' 
INNER JOIN Events e 
ON(f.SenderId = e.SenderId OR f.SenderId = e.ReceiverId 
OR f.ReceiverId = e.SenderId OR f.ReceiverId = e.ReceiverId) 
INNER JOIN Users u1 
ON (e.SenderId = u1.Id) 
INNER JOIN Users u2 
ON (e.ReceiverId = u2.Id) 
WHERE u.Id = @id;