以上示例代码中,替换your_collection和your_document为你需要操作的集合和文档名称。在checkDocument函数中,我们通过使用get()方法获取指定文档的快照,并检查snapshot的exists属性来判断文档是否存在。 腾讯云提供了云开发服务,其中包含了云数据库、云存储等服务,可用于构建基于云的应用。相关产品链接和介绍请参考腾讯云文档...
String fileName = 'your_file_name'; bool fileExists = false; void checkFileExists() async { DocumentSnapshot documentSnapshot = await firestore.collection('files').doc(fileName).get(); if (documentSnapshot.exists) { fileExists = true; print('File exists in Firestore.'); } el...
如果要检查单个文档,则需要使用另一个 if 语句。所以在你的实际中if (document.exists()){创建另一个看起来像这样的: Attendance attendance = document.toObject(Attendance.class); Date startTime = attendance.getStartTime(); Date endTime = attendance.getEndTime(); if(timeToCheck.after(startTime) &&...
//check if value exists const getDocument = await admin.firestore().doc(`${doc.ref.path}`).collection('AnalyseData').doc(`${year}`).get(); if (getDocument && getDocument.exists) { await document.update({ //map filled with data which gets added to the exisiting map }) } else { ...
checkNotNull(callback); // document reference points to the user document which is calling this method documentReference.get() .addOnSuccessListener((documentSnapshot) -> { ArrayList<DocumentReference> teacherReferences = (ArrayList<DocumentReference>) documentSnapshot.get("bookmarks"); Iterables.for...
The function can be null, so make sure to check that it exists before calling it. Note: This is not necessary to use. useDocument already unmounts the listener for you. This is only intended if you want to unsubscribe on your own.The...
update(todo, ['done']) // only send this value if it exists $fiery.update(todo, ['hidden']) // ignores exclude and include when specified // $fiery.save also takes fields, when you're not sure if your document exists.Encode & decode propertiesvar todos = $fiery(fs.collection('...
如果您遇到此问题，请确保您没有创建currentUser的示例。应用中任何位置的文档路径的.UID，除非用户已登录...
一些用户获得了身份验证，但没有将数据存储在我的Flutter应用程序的FireStore中而不是检查用户存在与否与...
一些用户获得了身份验证，但没有将数据存储在我的Flutter应用程序的FireStore中而不是检查用户存在与否与...