private static String makeSQL(java.sql.Date start, java.sql.Date end, String performers) {
        String sql = "";
        if (start == null && end == null && performers == "all") {
            sql = "SELECT * FROM reports";
        } else if (start == null && end == null) {
            sql = "SELECT * FROM reports WHERE \"perfofrmer\"=" + performers;

        } else if (start != null && end == null && performers == "all") {
            sql = "SELECT * FROM reports WHERE \"startdate\">=" + start;
        } else if (start == null && end != null && performers == "all") {
            sql = "SELECT * FROM reports WHERE \"finishdate\"<=" + end;
        } else if (start != null && end != null && performers == "all") {
            sql = "SELECT * FROM reports WHERE \"finishdate\"<=" + end + "AND \"startdate\">=" + start;
        } else if (start != null && end == null) {
            sql = "SELECT * FROM reports WHERE \"startdate\">=" + start + "AND \"performer\"=" + performers;   
        } else if (start == null && end != null) {
            sql = "SELECT * FROM reports WHERE \"finishhdate\"<=" + end + "AND \"performer\"=" + performers;
        } else if (start != null && end != null) {
            sql = "SELECT * FROM reports WHERE \"startdate\" >=" + start + "AND \"performer\"=" + performers + 
                    " AND \"finishdate\"<=" + end;
        }
        return sql;
    }