CODEWITHSUNDEEP
javascriptjsonnode.jsmongodbsails.js
Aravindh
Aravindh

Reputation: 451

Field name aliasing in mongoDB

I am using mongoDB and new to native command, I like to use alias name for the field name

here I am using two tables (Company and employee), In company table employee fields are associated with many to one association

My actual JSON is as follows. Table one and its name is "company"

comp_name : "YYYY",
employers : [
                {
                    name : "Mike",
                    status : "Active",
                    id : 01
                },{
                    name : "San",
                    status: "InActive",
                    id : 02
                }
            ],
status : "Active",
id : 00001

Table 2 and its name is "employee"

{
    name : "Mike",
    status : "Active",
    id : 01,
    company : {
                name : "YYYY",
                status : "Active",
                id : 00001
            }
},
{
    name : "San",
    status: "InActive",
    id : 02,
    company : {
                name : "YYYY",
                status : "Active",
                id : 00001
            }
}

I able to get the direct field as alias name in company table using the command 

Company.aggregate([
    {$match:{}},
    {$project:{c_name:"$comp_name",id:1}}
])

but i can't acheive it the data in employers in company table which status is "Active"

My expected JSON is, Table one and its name is "company"

c_name : "YYYY",
emp : [
                {
                    n : "Mike",
                    st : "Active",
                    id : 01
                }
            ],
st : "Active",
id : 00001

Table 2 and its name is "employee"

{
    n : "Mike",
    st : "Active",
    id : 01,
    comp : {
                n : "YYYY",
                st : "Active",
                id : 00001
            }
}

Upvotes: 0

Views: 4992

Answers (1)

Alex P.
Alex P.

Reputation: 3171

This would be for your company collection

db.company.aggregate([
{ $match:{ status: "Active"} }, // to only get the documents that have ths status
{ $unwind: "$employers"}, // to flatten your array
{ $match:{ "employers.status": "Active"} }, // match again for active employers
{ $project: { // for the final structure
    c_name: "$comp_name",
    emp: ["$employers"],
    st: "$status",
    id: 1
  }
}
])

Upvotes: 1

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