How to count subdocuments recursively - azure-cosmosdb

Question

I have documents in my db that look like this:
{
"id": "1"
"entityType": "node"
"childNodes": [
{
"id": "2"
"entityType": "node"
"childNodes": [
...
]
}
]
}
As a large tree structure.
I'd like to count the total number of documents and subdocuments in my collection that are of entityType = "Node".
My attempt is to get the data one level at a time manually:
SELECT VALUE COUNT(c.id) FROM c where CONTAINS(c.id, 'a|') and c.entityType = 'node'
SELECT VALUE COUNT(l.id) FROM c JOIN l in c.childNodes where CONTAINS(c.id, 'a|') and c.entityType = 'node'
SELECT VALUE COUNT(l2.id) FROM c JOIN l in c.childNodes JOIN l2 in l.childNodes where CONTAINS(c.id, 'a|') and c.entityType = 'node'

Answer 1

First of all, it's hard to find a smooth(direct) way to implement your needs.Surely,the manual way you mentioned in your question works.However,if you have too many layers of JSON nesting, or it's random,your way maybe inappropriate.
I would suggest you loop the result recursively to get the count of objects which contains "entityType": "node".For example, in the cosmos db stored procedure:
function sample(prefix) {
var collection = getContext().getCollection();
var isAccepted = collection.queryDocuments(
collection.getSelfLink(),
'SELECT c.childNodes FROM c where c.entityType = "node"',
function (err, feed, options) {
if (err) throw err;
if (!feed || !feed.length) {
var response = getContext().getResponse();
response.setBody('no docs found');
}
else {
var response = getContext().getResponse();
var count = {count:1};
loopChildNodes(feed,count);
response.setBody(count);
}
});
if (!isAccepted) throw new Error('The query was not accepted by the server.');
function loopChildNodes(array,count){
for (var i=0;i<array.length;i++){
console.log(count)
if(array[i].entityType == "node"){
count.count++;
}
if(array[i].childNodes!=null)
loopChildNodes(array[i].childNodes,count)
}
}
}
My test data:
Output: