Cosmos equivalent of map / select - azure-cosmosdb

Question

clients is an array inside my doc, the following query
SELECT
f.id, f.clients
FROM f
where f.id ="35fb0733-dfa1-4932-9690-3ee5b05d89ff"
Returns
[
"id": "35fb0733-dfa1-4932-9690-3ee5b05d89ff",
{
"clients": [
{
"firstname": "Benjamin",
"surname": "Bob",
},
{
"firstname": "Rachael",
"surname": "Smith",
}
]
}
]
But I would like clients to look like :
"firstnames": [ "Benjamin", "Rachael" ]
"surnames": [ "Bob", "Smith" ]
Is this possible?

Answer 1

You could use the ARRAY expression w/ a subquery to achieve that.
Try this query:
SELECT
ARRAY(SELECT VALUE client.firstname FROM client IN f.clients) AS firstnames,
ARRAY(SELECT VALUE client.surname FROM client IN f.clients) AS surnames
FROM f

Answer 2

Just give an additional option, you could use stored procedure to get the results you want.
function sample() {
var collection = getContext().getCollection();
var isAccepted = collection.queryDocuments(
collection.getSelfLink(),
'SELECT f.id, c.firstname,c.surname FROM f join c in f.clients where f.id ="1"',
function (err, feed, options) {
if (err) throw err;
var map = {};
var firstname = [];
var surname =[];
if (!feed || !feed.length) {
var response = getContext().getResponse();
response.setBody('no docs found');
}
else {
for(var i=0;i<feed.length;i++){
map["id"] = feed[i].id;
firstname.push(feed[i].firstname);
surname.push(feed[i].surname);
}
map["firstname"] = firstname;
map["surname"] =surname;
var response = getContext().getResponse();
response.setBody(map);
}
});
if (!isAccepted) throw new Error('The query was not accepted by the server.');
}
Test Output:
{
"id": "1",
"firstname": [
"Benjamin",
"Rachael"
],
"surname": [
"Bob",
"Smith"
]
}