MongoDB aggregate + $match + $group + Array - mongodb

Question

Here is my MongoDB query :
profiles.aggregate([{"$match":{"channels.sign_up":true}},{"$group":{"_id":"$channels.slug","user_count":{"$sum":1}}},{"$sort":{"user_count":-1}}])
Here is my Code :
$profiles = Profile::raw()->aggregate([
[
'$match' => [
'channels.sign_up' => true
]
],
[
'$group' => [
'_id' => '$channels.slug',
'user_count' => ['$sum' => 1]
]
],
[
'$sort' => [
"user_count" => -1
]
]
]);
Here is my Mongo Collection :
"channels": [
{
"id": "5ae44c1c2b807b3d1c0038e5",
"slug": "swachhata-citizen-android",
"mac_address": "A3:72:5E:DC:0E:D1",
"sign_up": true,
"settings": {
"email_notifications_preferred": true,
"sms_notifications_preferred": true,
"push_notifications_preferred": true
},
"device_token": "ff949faeca60b0f0ff949faeca60b0f0"
},
{
"id": "5ae44c1c2b807b3d1c0038f3",
"slug": "website",
"mac_address": null,
"device_token": null,
"created_at": "2018-06-19 19:15:13",
"last_login_at": "2018-06-19 19:15:13",
"last_login_ip": "127.0.0.1",
"last_login_user_agent": "PostmanRuntime/7.1.5"
}
],
Here is my response :
{
"data": [
{
"_id": [
"swachhata-citizen-android"
],
"user_count": 1
},
{
"_id": [
"icmyc-portal"
],
"user_count": 1
},
{
"_id": [
"swachhata-citizen-android",
"website",
"icmyc-portal"
],
"user_count": 1
}
]
}
what i am expecting is :
{
"data": [
{
"_id": [
"swachhata-citizen-android"
],
"user_count": 1
},
{
"_id": [
"icmyc-portal"
],
"user_count": 1
},
{
"_id": [
"website",
],
"user_count": 1
}
]
}
As you can see channels is an array and "sign_up" is true only for one element in array from where user is registered as we have many app so we have to maintain more than 1 channel for users.
i want to data how many user registered with different channels but in response its coming all the channel instead of one channel where sign_up is true.
Also count is wrong as i have to records where "slug": "swachhata-citizen-android" and "sign_up": true.
Need suggestion :)

Answer 1

Use $unwind to transform each document with arrays to array of documents with nested fields. In your example, like this:
profiles.aggregate([
{$unwind: '$channels'},
{$match: {'channels.sign_up': true}},
{$group: {_id: '$channels.slug', user_count: {$sum: 1}}},
{$sort: {user_count: -1}}
])