[英]How do i get the key UID of a node with a selected value in firebase database in android?
[英]How do I get/retrieve multiple data from uid in the firebase database in android?
如何使用以下代碼從 firebase 獲取數據?
登錄成功后出現空指針異常?
DatabaseReference mref = FirebaseDatabase.getInstance().getReference().child("/Users/Students")
.child(FirebaseAuth.getInstance().getCurrentUser().getUid());
mref.addValueEventListener(new ValueEventListener() {
@SuppressLint("SetTextI18n")
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
for (DataSnapshot ds : dataSnapshot.getChildren()){
email = ds.child("email").getValue().toString();
full_name = ds.child("full_name").getValue().toString();
roll_number = ds.child("roll_number").getValue().toString();
admission_id = ds.child("admission_id").getValue().toString();
phone_no = ds.child("phone_number").getValue().toString();
branch = ds.child("branch").getValue().toString();
year = ds.child("year").getValue().toString();
semester = ds.child("semester").getValue().toString();
section = ds.child("section").getValue().toString();
course = ds.child("course").getValue().toString();
batch = ds.child("batch").getValue().toString();
dob = ds.child("dob").getValue().toString();
address = ds.child("address").getValue().toString();
}
}
我的 Firebase 數據庫是:
刪除以下內容:
for (DataSnapshot ds : dataSnapshot.getChildren()){
由於您已經可以訪問 uid,因此您不需要在直接子級內部循環來獲取值。
所以只需這樣做:
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
email = dataSnapshot.child("email").getValue().toString();
full_name = dataSnapshot.child("full_name").getValue().toString();
roll_number = dataSnapshot.child("roll_number").getValue().toString();
admission_id = dataSnapshot.child("admission_id").getValue().toString();
phone_no = dataSnapshot.child("phone_number").getValue().toString();
branch = dataSnapshot.child("branch").getValue().toString();
year = dataSnapshot.child("year").getValue().toString();
semester = dataSnapshot.child("semester").getValue().toString();
section = dataSnapshot.child("section").getValue().toString();
course = dataSnapshot.child("course").getValue().toString();
batch = dataSnapshot.child("batch").getValue().toString();
dob = dataSnapshot.child("dob").getValue().toString();
address = dataSnapshot.child("address").getValue().toString();
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.