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嘿,我想將具有多個子節點的子節點內的數據複製到另一個地方。將具有多個子節點的Firebase節點複製到另一個節點
在上述圖像我想將數據傳輸的問題節點內部分成用戶的UID節點。
在問題節點值中,我有兩個字段,即正確答案和圖片url。
我曾嘗試以下
public void copyFirebaseData() {
DatabaseReference questionNodes = FirebaseDatabase.getInstance().getReference().child("questions");
final DatabaseReference toUsersQuestions = FirebaseDatabase.getInstance().getReference().child("users").child(uid).child("questions");
questionNodes.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
toUsersQuestions.setValue(dataSnapshot.getValue(), new Firebase.CompletionListener() { //getting error in this line
@Override
public void onComplete(FirebaseError firebaseError, Firebase firebase) {
if (firebaseError != null)
System.out.println("Copy failed");
else
System.out.println("Success");
}
});
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
}`
但這拋出異常
02-24 13:47:09.085 7757-7757/curieo.android.zenmaster E/AndroidRuntime: FATAL EXCEPTION: main
Process: curieo.android.zenmaster, PID: 7757
com.google.firebase.database.DatabaseException: Failed to parse node with class class curieo.android.zenmaster.mainfragments.HomeFragment$11$1
at com.google.android.gms.internal.zzbpf.zza(Unknown Source)
at com.google.android.gms.internal.zzbpf.zzar(Unknown Source)
at com.google.android.gms.internal.zzbpi.zzas(Unknown Source)
at com.google.firebase.database.DatabaseReference.setValue(Unknown Source)
at curieo.android.zenmaster.mainfragments.HomeFragment$11.onDataChange(HomeFragment.java:750)
at com.google.firebase.database.Query$1.onDataChange(Unknown Source)
at com.google.android.gms.internal.zzbmz.zza(Unknown Source)
at com.google.android.gms.internal.zzbnz.zzYj(Unknown Source)
at com.google.android.gms.internal.zzboc$1.run(Unknown Source)
at android.os.Handler.handleCallback(Handler.java:815)
at android.os.Handler.dispatchMessage(Handler.java:104)
at android.os.Looper.loop(Looper.java:207)
at android.app.ActivityThread.main(ActivityThread.java:5740)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:905)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:766)
如何節省下的問題點的全部數據,並將其複製到UID節點。 任何幫助將是偉大的
您是否曾嘗試將值添加到對象中,然後使用該對象設置值? (只是好奇) – koceeng
不,我沒有。我已經使用這個例子http://stackoverflow.com/questions/40456443/how-to-move-firebase-child-from-one-node-to-another-in-android其中說,這是正確的做法它。 @koceeng –
'HomeFragment'line 750 is toUsersQuestions.setValue(...',right? – koceeng