[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
我正在尝试通过在Android Studio中使用子项“ UID”来获取父级名称“ 170002001”。 请帮忙。 提前致谢 :)
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) {
}
});
}
编辑:除了“ 170002001”,我能够检索所有父名称。 :(
将其放在onDataChange(DataSnapshot dataSnapshot)
侦听器中
String parent = dataSnapshot.getKey();
由于firebase会为此管理可能的父键列表,因此请执行此操作
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);
}
}
请注意,这里的引用将是"170002001"
键上方的节点,该键是所有这些键的父级
编辑:如果要在每个节点中获取所有UID,请执行此操作
创建一个POJO类来保存该用户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;
}
}
然后像上面一样做
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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