Aggregation on multi field

Question

Reading MongoDb documentation about aggregation operation, I've found this:

db.orders.aggregate(
    [
        { $match: { status: "A" } },
        { $group: { _id: "$cust_id", total: { $sum: "$amount" } } },
        { $sort: { total: -1 } }
    ],
    {
         explain: true
    }

)

But, suppose I have another field named phone, how can I aggregate about cust_id and phone?

I've tried as follow:

{ $group: { _id: {"$cust_id", "$phone"}, total: { $sum: "$amount" } } },

But doesn't work

EDIT

I want this behaviour:

SELECT SUM(amount)
FROM orders
GROUP BY cust_id, phone

But I have this error (I must attach screenshot because by MongoChef I can't textual error):

*doesn't work* is not a problem statement. What you expect, and what you get instead? — Alex Blex, Mar 02 '17 at 09:31
possible duplicate: http://stackoverflow.com/questions/22932364/mongodb-group-values-by-multiple-fields — RudyVerboven, Mar 02 '17 at 09:43

score 2 · Accepted Answer · answered Mar 02 '17 at 09:41

2

There is nothing to explain. It's just wrong syntax. Objects should have field names, not only field values. E.g.:

{ $group: { _id: {id:"$cust_id", phone:"$phone"}, total: { $sum: "$amount" } } },

answered Mar 02 '17 at 09:41

Alex Blex

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Thanks! It's very simple, my fault! – Joe Taras Mar 02 '17 at 09:47

Aggregation on multi field

1 Answers1