从Android Studio中的Firebase检索
我的firebase数据库的结构如下所示:从Android Studio中的Firebase检索,android,firebase,firebase-realtime-database,Android,Firebase,Firebase Realtime Database,我的firebase数据库的结构如下所示: -Details -BNFJ3491 -Answer: "abc" -Name: "ABC" -Password:"cde" -Security Question: "rgrg" -User Type: "Student" -CBTV15873 -Answer: "abc" -Name: "ABC" -Pass
-Details
-BNFJ3491
-Answer: "abc"
-Name: "ABC"
-Password:"cde"
-Security Question: "rgrg"
-User Type: "Student"
-CBTV15873
-Answer: "abc"
-Name: "ABC"
-Password:"cde"
-Security Question: "rgrg"
-User Type: "Student"
-Notices
-B tech placement
-Department: "Urja Mandir"
-Matter: "Hello welcome to btech placement cell"
我不知道如何获取特定id的密码(如BNFJ3491)。datasnapshot将获取所有数据,但如何检索特定id的信息。请使用以下代码:
Firebase ref=new Firebase("https://linkb-873e1.firebaseio.com/Details");
ref.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
String password = dataSnapshot.child(-BNFJ3491).child("Password").getValue();
}
@Override
public void onCancelled(FirebaseError firebaseError) {
System.out.println("The read failed: " + firebaseError.getMessage());
}
});
您可以使用此代码
ref.child(userId).addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
String password = dataSnapshot.child("Password").getValue(String.class);
}
@Override
public void onCancelled(DatabaseError databaseError) {}
});
谢谢你的帮助!
ref.child(userId).addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
String password = dataSnapshot.child("Password").getValue(String.class);
}
@Override
public void onCancelled(DatabaseError databaseError) {}
});