MongoDB Aggregate shows no result

Question

I am trying to make a group by in Mongo and the problem is that I'm getting no result. I want to do the equivalent to:

select nodo, count(*) as cantidad group by nodo

So, my Mongo query is:

var start = ISODate("2018-08-01T00:00:00.000Z").getTime() / 1000;
var end = ISODate("2018-08-01T23:59:59.000Z").getTime() / 1000;

print("nodo;cantidad");
db.reclamosTecnicos.aggregate([
    { $group : { _id : "$cliente.nodoCrm", cantidad : {$sum : 1} } },
    { $match : { tipoResolucion: {$eq: 0}, fechaCarga: { $gt: start, $lt: end } } }
]).forEach(function(doc){
print(doc._id+";"+doc.cantidad);
})

But I'm getting no result. I thought the problem was the $match part, but if I run this separately I get a result, as you can see in this image:

Can you see what I'm doing wrong?

Answer 1

Your $match stage should be the first stage before the $group .

db.reclamosTecnicos.aggregate([
  { $match : { tipoResolucion: {$eq: 0}, fechaCarga: { $gt: start, $lt: end } } },
  { $group : { _id : "$cliente.nodoCrm", cantidad : {$sum : 1} } }
])

Answer 2

正如 Anthony 在评论中所说，我不得不将 $match 放在 $group 之前。