在客户端获取快照大小 - Firestore javascript

Question

我正在查询 firestore 以获取一些结果。但是在运行 forEach 循环文档之前，我想知道 集合快照 中是否有任何文档，并且 snapshot.exist() 总是给出 false 即使里面有文档

db.collection("users").where("mobile_no", '==', mobileToCheck).get().then(function(querySnapshot){
            if (querySnapshot.exists) {        \THIS ALWAYS RETURNING FALSE
                querySnapshot.forEach(doc => {
                     console.log(doc.data());
                });
                console.log(mobileToCheck + "Exist In DB");
            }else{
                console.log(mobileToCheck + "Do Not Exist In DB");
            }
        });

我怎么知道有没有结果？

Answer 1

QuerySnapshot object doesn't have an exists property, that one is only available on DocumentSnapshots.

您可以检查 querySnapshot.empty or querySnapshot.size

在客户端获取快照大小 - Firestore javascript

Get snapshot size on client side - Firestore javascript

javascript

firebase

google-cloud-firestore