Mysql query probleem

	$sql = "SELECT 
                    tk.id,
		    pr.naam,
		    tk.subproject_id,
		    tk.taak_naam,
		    tk.ges_startdatum,
	            tk.ges_einddatum,
		    tk.status,
		    tk.regie,
		    sp.subproject_naam
		 FROM 
		    taken tk 
		 JOIN 
		    projecten pr 
		 ON 
		    pr.id = tk.project_id
		 JOIN
		    subprojecten sp
		 ON
		    tk.subproject_id = sp.id";