如果 firestore 中不存在该集合,我将尝试创建该集合。
我的代码如下
val docRef = fbase.collection("cities").document("LA")
docRef.get().addOnSuccessListener {
document ->
if(document!= null){
Toast.makeText(this, "Already exists", Toast.LENGTH_LONG).show()
}
else{
FireBaseRepository
Toast.makeText(this, "Does not exists", Toast.LENGTH_LONG).show()
}
}
'FireBaseRepository' 只是一个带有初始化集合的类。由于 FirebaseFirestore.java 类确保集合不能为空,我的代码总是通过 if 条件。我已经查看了推荐链接 https://firebase.google.com/docs/firestore/query-data/get-data?hl=en。
@NonNull
public CollectionReference collection(@NonNull String collectionPath) {
checkNotNull(collectionPath, "Provided collection path must not be null.");
ensureClientConfigured();
return new CollectionReference(ResourcePath.fromString(collectionPath), this);
}
答案 0 :(得分:0)
您必须检查以下代码
if(!document.exists()){
Toast.makeText(this, "Does not exists", Toast.LENGTH_LONG).show()
FireBaseRepository
}
else{
Toast.makeText(this, "Already exists", Toast.LENGTH_LONG).show()
}