Question

我想从firestore的集合中获取数据（语言字段），并带有where子句，但是它不起作用。

我的代码：

db = FirebaseFirestore.getInstance();
Query query = db.collection(collection).whereGreaterThan("longtitude", String.valueOf(bounds.northeast.latitude));
query.addSnapshotListener(new EventListener<QuerySnapshot>() {
            @Override
            public void onEvent(@javax.annotation.Nullable QuerySnapshot queryDocumentSnapshots, @javax.annotation.Nullable FirebaseFirestoreException e) {
                if (e != null) {
                    Log.w(TAG, "Listen failed.", e);
                    return;
                }

                if (queryDocumentSnapshots != null) {
                    Log.d(TAG, queryDocumentSnapshots.getMetadata().toString());        
                } else {
                    Log.d(TAG, "Current data: null");
                }
            }
        });

我只能得到

SnapshotMetadata{hasPendingWrites=false, isFromCache=false}

但是我要从集合中获取字段。怎么做？

我尝试了不同的方法，但没有一个方法返回集合中的字段。

Answer 1

对集合运行查询时，会得到一个function detectProxy() { $sockport = false; $proxyports=array(80,8080,6588,8000,3128,3127,3124,1080,553,554); for ($i = 0; $i <= count($proxyports); $i++) { if(@fsockopen($ipaddress,$proxyports[$i],$errstr,$errno,0.5)){ $sockport=true; } } if( isset($_SERVER['HTTP_VIA']) || isset($_SERVER['HTTP_X_FORWARDED_FOR']) || isset($_SERVER['HTTP_FORWARDED_FOR']) || isset($_SERVER['HTTP_X_FORWARDED']) || isset($_SERVER['HTTP_FORWARDED']) || isset($_SERVER['HTTP_CLIENT_IP']) || isset($_SERVER['HTTP_FORWARDED_FOR_IP']) || isset($_SERVER['VIA']) || isset($_SERVER['X_FORWARDED_FOR']) || isset($_SERVER['FORWARDED_FOR']) || isset($_SERVER['X_FORWARDED']) || isset($_SERVER['FORWARDED']) || isset($_SERVER['CLIENT_IP']) || isset($_SERVER['FORWARDED_FOR_IP']) || isset($_SERVER['HTTP_PROXY_CONNECTION']) || $sockport === true ) { echo 'User is using proxy'; } else{ echo ''user is not using proxy'; } }，其中可以包含零个或多个文档。要获取实际的文档，您需要像here所示那样遍历文档：

QuerySnapshot

如何使用where子句从firestore中的集合中获取数据？

1 个答案: