"how to use multiple orederbychild in firebase database?" Code Answer

firebase realtime database does not support multiple where clauses. so try to query with one filter and then filter the next one programatically.

search_button.setonclicklistener(new view.onclicklistener() {
        @override
        public void onclick(view v) {


            system.out.println("default selected"+sel_blood_group);
            system.out.println("default selected"+sel_area);


            mfirebasedatabase.addlistenerforsinglevalueevent(new valueeventlistener() {
                @override
                public void ondatachange(datasnapshot datasnapshot) {
                    //your logic here
                    for (datasnapshot eventsnapshot : datasnapshot.getchildren()) {
                        userregistermodel mmodel = eventsnapshot.getvalue(userregistermodel.class);
                       // log.e("data" ,""+ mmodel.getname());
                    }


                    query chatroomsquery = mfirebasedatabase.orderbychild("blood_group").equalto(sel_blood_group);

                    chatroomsquery.addlistenerforsinglevalueevent(new valueeventlistener() {
                        @override
                        public void ondatachange(datasnapshot datasnapshot) {
                            if (datasnapshot.exists()) {
                                // datasnapshot is the "issue" node with all children with id 0
                                for (datasnapshot issue : datasnapshot.getchildren()) {
                                    // do something with the individual "issues"
                                    userregistermodel mmodel = issue.getvalue(userregistermodel.class);
                                   if(mmodel.getarea().equals(sel_area))
                                    log.e("query data" ,""+ mmodel.getname());
                                }
                            }
                        }

                        @override
                        public void oncancelled(databaseerror databaseerror) {

                        }
                    });
                    log.e("data" ,""+ chatroomsquery.tostring());
                }

                @override
                public void oncancelled(databaseerror databaseerror) {

                }
            });
        }
    });enter code here