Mongodb group and sort

Question

How can I translate the following Sql query for Mongo?:

select a,b,sum(c) csum from coll wh         


        

Answer 1

I want to add the following query, as an example, it may be useful in case of two groupings.

Query:

db.getCollection('orders').aggregate([
    {$match:{
        tipo: {$regex:"[A-Z]+"}
        }
    },
    {$group:
        { 
            _id:{
                codigo:"1",
                fechaAlta:{$substr:["$fechaAlta",0,10]},
            },
            total:{$sum:1}
        }
    },
    {$sort:
        {"_id":1}
    },
    {$group:
        {
            _id:"$_id.codigo",
            fechasAltas:
            {
                $push:
                {
                    fechaAlta:"$_id.fechaAlta",
                    total:"$total"
                }
            },
            totalGeneral:{$sum:"$total"}
        }
    }
]); 

Response:

{
"_id" : "1",
"fechasAltas" : [ 
    {
        "fechaAlta" : "1940-01-01",
        "total" : 13.0
    }, 
    {
        "fechaAlta" : "2007-05-14",
        "total" : 115.0
    }, 
    {
        "fechaAlta" : "2008-09-30",
        "total" : 58.0
    }, 

    .
    .
    .
],
"totalGeneral" : 50620.0
}