Develop Reference

Save button deletes previous data in firebase

I am new to android studio and firebase. I am trying to save a list of people to firebase like this. Idea is that the logged in user should be able to save information about some people.
String userId = user.getCurrentUser().getUid();
databaseReference.child("users").child(userId).child("savedPersons").child("name").setValue(nameTxt);
databaseReference.child("users").child(userId).child("savedPersons").child("surname").setValue(surnameTxt);
databaseReference.child("users").child(userId).child("savedPersons").child("gender").setValue(genderTxt);
databaseReference.child("users").child(userId).child("savedPersons").child("ageTxt").setValue(ageTxt);
It does not surprise me that it deletes the previous saved person when i save another one but i don't know how to save all of them. I have this in my firebase but i need multiple saved users. How do i do it ?
Firebase screenshot

If you want to save multiple people in a list in the database, you'll want to call push:
String userId = user.getCurrentUser().getUid();
DatabaseReference newRef = databaseReference.child("users").child(userId).child("savedPersons").push(); // 👈
newRef.child("name").setValue(nameTxt);
newRef.child("surname").setValue(surnameTxt);
newRef.child("gender").setValue(genderTxt);
newRef.child("ageTxt").setValue(ageTxt);
This will create a new child node under savedPersons each time you call push(). To learn more on this, see the Firebase documentation on appending data to a list.
Note that calling setValue for each property is wasteful, and may lead to unexpected behavior down the line. I recommend putting all values in a map, and then adding them all with one call to setValue:
Map<String, Object> values = new Map<>();
values.put("name", nameTxt);
values.put("surname", surnameTxt);
values.put("gender", genderTxt);
values.put("ageTxt", ageTxt);
newRef.setValue(values);

GAE JAVA - Getting Object by Property

I have Entity say, User { id (primary_key), phone } to be stored in Datastore.
While Retrieving same i can use getObjectById(User.class,id) to get object. Is there way to get object with non-key property, say phone.
As per the documentation, Datastore creates index updates for Property "phone" too.
How do we use this index to get result?

You can simply use a JDO Query like following and Datastore will query on the non-key phone property (assuming you haven't set to to be unindexed).
q = pm.newQuery(User.class,"phone == '1234567890'");

Unable to retrive Projection/Multi- Relantion field Requests.Custom_SFDCChangeReqID2 using versionone java sdk

I have been trying to retrieve information from querying a specific Asset(Story/Defect) on V1 using the VersionOne.SDK.Java.APIClient. I have been able to retrieve information like ID.Number, Status.Name but not Requests.Custom_SFDCChangeReqID2 under a Story or a Defect.
I check the metadata for:
https://.../Story?xsl=api.xsl
https://.../meta.V1/Defect?xsl=api.xsl
https://.../meta.V1/Request?xsl=api.xsl
And the naming and information looks right.
Here is my code:
IAssetType type = metaModel.getAssetType("Story");
IAttributeDefinition requestCRIDAttribute = type.getAttributeDefinition("Requests.Custom_SFDCChangeReqID2");
IAttributeDefinition idNumberAttribute = type.getAttributeDefinition("ID.Number")
Query query = new Query(type);
query.getSelection().add(requestCRIDAttribute);
query.getSelection().add(idNumberAttribute);
Asset[] results = v1Api.retrieve(query).getAssets();
String RequestCRID= result.getAttribute(requestCRIDAttribute).getValue().toString();
String IdNumber= result.getAttribute(idNumberAttribute).getValue().toString();
At this point, I can get some values for ID.Number but I am not able to retrieving any information for the value Custom_SFDCChangeReqID2.
When I run the restful query to retrieve information using a browser from a server standpoint it works and it does retrieve the information I am looking for. I used this syntax:
https://.../rest-1.v1/Data/Story?sel=Number,ID,Story.Requests.Custom_SFDCChangeReqID2,Story.

Alex: Remember that Results is an array of Asset´s, so I guess you should be accessing the information using something like
String RequestCRID= results[0].getAttribute(requestCRIDAttribute).getValue().toString();
String IdNumber= results[0].getAttribute(idNumberAttribute).getValue().toString();
or Iterate through the array.
Also notice that you have defined:
Asset[] results and not result

Hi thanks for your answer! I completely forgot about representing the loop, I was too focus on the retriving information part, yes I was actually using a loop and yes I created a temporary variable to check what I was getting from the query in the form
Because I was getting the variables one by one so I was only using the first record. My code works after all. It was just that What I was querying didn't contain any information of my use, that's why I was not finding any. Anyway thanks for your comment and observations

Google App Engine Query .addFilter

I've been struggling with queries with Google's datastore and wanted to get some help.
I have a form that saves a double to the datastore. Here is a snippet from the servlet:
String temp = req.getParameter("temp");
message.setProperty("temp", temp);
temp is a string but containes a number with decimal places.
In my JSP code I'm trying to run the query:
query.addFilter("temp",Query.FilterOperator.GREATER_THAN, -0.9);
But it only seems to work if the value (-0.9) is an integer (-1). Also, when I try to use a variable I get an invalid constant error:
query.addFilter("temp",Query.FilterOperator.GREATER_THAN, request.getParameter('mintemp'));
Any help would be appreciated!
Thanks!

Chance are you are setting your property as a String, you should store the property as a Float instead see the documentation for setProperty.
Convert your String to a Float before setting the Entity property:
message.setProperty("temp", Float.parseFloat(temp));

JDO - List of Strings not being retrieved from database

On my User class I have a field that is a list of strings:
#Persistent
private List<String> openIds;
When I create a new user I do this:
User user = new User();
user.openIds.add(openid);
pm.makePersistent(user);
When I break after that last line and look, the openIds contains the openid I put in there.
But, when I later call User user = pm.getObjectById(User.class, id); with the correct id, the openIds field is an empty list.
Anyone know what could cause that?
EDIT: BTW I'm running on the Google App Engine
UPDATE: Looking at the datastore viewer, I can see the openid was correctly stored in the database. So its just not getting it out correctly...
UPDATE 2: Its working fine now. I'm pretty sure I didn't change anything. I think what must have happened is that there was an old version of the user object being pulled from the database. A user object that was put in before I had the code that saves the openid. Once I wiped the database things worked fine.

Not putting that field in the fetch plan ?
Accessing persistent fields directly, rather than going via setters ?