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[英]Get Value of Key Based on the Parent Child of Current User Firebase Android
[英]Get parent name using child key in firebase android
我正在嘗試通過在Android Studio中使用子項“ UID”來獲取父級名稱“ 170002001”。 請幫忙。 提前致謝 :)
private void getdata(){
DatabaseReference reference;
reference = FirebaseDatabase.getInstance().getReference();
reference.orderByChild("UID").equalTo(uid).addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
for (DataSnapshot childSnapshot: dataSnapshot.getChildren()) {
keys = childSnapshot.getKey();
status.setText(keys);
}
}
@Override
public void onCancelled(@NonNull DatabaseError databaseError) {
}
});
}
編輯:除了“ 170002001”,我能夠檢索所有父名稱。 :(
將其放在onDataChange(DataSnapshot dataSnapshot)
偵聽器中
String parent = dataSnapshot.getKey();
由於firebase會為此管理可能的父鍵列表,因此請執行此操作
DatabaseReference reference;
reference = FirebaseDatabase.getInstance.getReference();
reference.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
for (DataSnapshot childSnapshot: dataSnapshot.getChildren()) {
String parent = childSnapshot.getKey();
Log.i(TAG,parent);
}
}
請注意,這里的引用將是"170002001"
鍵上方的節點,該鍵是所有這些鍵的父級
編輯:如果要在每個節點中獲取所有UID,請執行此操作
創建一個POJO類來保存該用戶ID
public class UserPojo {
private String UID;
public UserPojo(String UID) {
this.UID = UID;
}
public UserPojo() {
}
public String getUID() {
return UID;
}
public void setUID(String UID) {
this.UID = UID;
}
}
然后像上面一樣做
reference.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
for (DataSnapshot childSnapshot: dataSnapshot.getChildren()) {
String parent = childSnapshot.getKey();
UserPojo user = childSnapshot.getValue(UserPojo.class);
//get your User ID
String user = user.getUID();
Log.i(TAG,parent);
}
}
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