how do i count number of admins in mongoose? - mongodb

Question

when i perform the following aggregate.my expectation is to get roles count for dashboard as expected in my output below but what i am getting is 0 for admin,extension,seeder values respectively. what do you think is my mistake?
model
var Schema = mongoose.Schema(
{
username: String,
email: String,
password: String,
roles: [
{
type: mongoose.Schema.Types.ObjectId,
ref: "Role"
}
],
},
{ timestamps: true }
);
This is the aggregate i am working on...
controller
exports.userRoleCount = (rep,res,next) =>{
User.aggregate([
{$project: {
admin: {$cond: [{$eq: ["$roles", "['admin']"]}, 1, 0]},
seeder: {$cond: [{$eq: ["$roles", "seeder"]}, 1, 0]},
extension: {$cond: [{$eq: ["$roles", "extension"]}, 1, 0]},
}},
{$group: { _id: null, admin: {$sum: "admin"},
seeder: {$sum: "$seeder"},
extension: {$sum: "$extension"},
total: {$sum: 1},
}},
], (error,data)=>{
if (error){
return next(error);
} else {
res.json(data);
}
}
)
This is the output i get
output
{
"_id": null,
"admin": 0,
"seeder": 0,
"extension": 0,
"total": 9
}
My expectation was this.....
{
"_id": null,
"admin": 3,
"seeder": 4,
"extension": 2,
"total": 9
}
This is my roles array...
db.ROLES = ["user", "admin", "extension", "seeder"];

Answer 1

Hi,
{$unwind : "$roles"},
{$group: { _id: null,
admin: {$sum: {$eq : ["roles": "admin"]}},
seeder: {$sum: {$eq : ["roles": "seeder"]}},
total: {$sum: 1},
}},

Answer 2

I have changed the code fragment as follow and it worked!!
exports.userRoleCount = (rep,res,next) =>{
User.aggregate([
{
"$project": {
"_id": 1,
"roles": 1
}
},
{
"$unwind": "$roles"
},
{
"$group": {
"_id": '$roles',
"count": {"$sum": 1}
}
},
{"$sort": {"_id": -1}},
{"$limit": 5}
], (error,data)=>{
if (error){
return next(error);
} else {
res.json(data);
// console.log(data[1].count);
}
}
)
}
And the output looks like as follow
{
{
_id:1 // this id is for role admin
count: 2
},
{
_id:2 // this id is for role extension
count: 5
}
}