android - 如何在 firebase Android 中搜索 Child 的值

Question

DatabaseReference databaseReference=mDatabase;
        String queryText="Hotel";
        databaseReference.orderByChild("Coupon")
                .startAt(queryText)
                .endAt(queryText+"\uf8ff");

Here I attached the code which I used to get child names of "Coupon" when I entered the "Hotel" query under the Coupon.But I got blank.I supposed to get Hotel1,Hotel2 object.I'm new to firebase.So hope your support .Thanks in advance.

Answer 1

在网络版本中，他们使用称为 ElasticSearch 的东西，您可以尝试在此处阅读更多内容:https://firebase.googleblog.com/2014/01/queries-part-2-advanced-searches-with.html

但是对于 Android，我认为没有任何功能可以执行这样的搜索。我要做的就是查询所有记录，然后自己过滤它们:

DatabaseReference databaseReference = mDatabase;
mDatabase.addValueEventListener(new ValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
    for(DataSnapshot val : dataSnapshot.getChildren()){
        //I am not sure what record are you specifically looking for
        //This is if you are getting the Key which is the record ID for your Coupon Object
        if(val.getKey().contains("Hotel")){
            //Do what you want with the record
        }

        //This is if your are querying for the hotel child
        if(val.child("hotel").getValue(String.class).contains("Hotel")){
            //Do what you want with the record
        }
    }
}
@Override
public void onCancelled(FirebaseError firebaseError) {

}

}