Node JS and Firebase Unable to Search Using equal.To() - node.js

Question

I've started reading into creating Google Actions using Node.JS/Dialogflow/Firebase.
I have reached a big stumbling block, in trying to get a simple code running that would search a Firebase database for a certain value and then report back. For example from the JSON output, I would like to search for the applicationID and have the age passed back as the output.
I would be extremely grateful if someone can review my code and direct me in the right direction.
Table Structure
{
"groupA" : {
"applications" : {
"100" : {
"age" : 20,
"result" : "pass"
},
"200" : {
"age" : 25,
" result " : "pass"
},
"500" : {
"age" : 20,
" result " : "fail"
}
}
}
}
Node JS
return admin.database().ref('groupA').child('applications').orderByChild('applications').equalTo(500)
.once('value')
.then(acceptedApplicationsSnapshot => {
var id = acceptedApplicationsSnapshot.val().age;
var data = acceptedApplicationsSnapshot.val();
var theAge = acceptedApplicationsSnapshot.child("age").val();
agent.add('some random text' + theAge);
});
Within this example the value 500 should be searched with the age then given as the output.

Answer 1

You're ordering/filtering on property applications, but the value you're passing in is a key. So you'll want to use orderByKey instead of orderByChild:
return admin.database().ref('groupA').child('applications').orderByKey().equalTo(500)
A query may match multiple child nodes, so the above returns a snapshot with a list of results. Even when there's only one result, the query will return a list of one result:
{
"500": {
"age" : 20,
" result " : "fail"
}
}
This means that you'll need to loop over the results in your callback:
acceptedApplicationsSnapshot.forEach(appSnapshot => {
var theAge = appSnapshot.child("age").val();
agent.add('some random text' + theAge)
})
Since you know the exact key of the child node you want, you can also simply keep using child() to access the specific node:
return admin.database().ref('groupA').child('applications').child('500')
This will result in a snapshot of that specific node being returned, instead of the list-with-a-single-child-node of the previous snippet.
{
"age" : 20,
" result " : "fail"
}
And then you can use your existing code to retrieve the age from the snapshot.

Answer 2

To search for the applicationsID=500 and have the age passed back as the output, you can try this.
var db = admin.database();
var ref = db.ref("groupA").child("applications/500").once('value')
.then(function(dataSnapshot){
console.log(dataSnapshot.val().age);
});
More info here.
Edited: This should give you the age, in this case equals 20, for the parameter you pass in applications/500 in the code above.
Let me know if it helps.