How to find documents using a field of an embedded document that is inside an array? - mongodb

Question

I have the Data/Schema for my student records:
{
"_id" : ObjectId("579ed0ba7d509178a97fae8f"),
"fullName" : "ABC",
"enroll" : "AB1234",
"profile" : {
"isCompleted" : true,
"verification" : [
{
"pro" : true,
"verifiedBy" : "ProAct",
"verifiedOn" : ISODate("2016-09-12T07:36:53.680Z")
},
],
"isChecked" : false,
"fullName" : "ABC",
"gender" : "Male",
"emergencyContactPerson" : {
"name" : "Father",
"mobile" : "9412345678",
"email" : "example#gmail.com",
},
},
"contact" : {
"emailID" : {
"isVerified" : true,
"isChecked" : false,
"verificationTokenExpiresIn" : ISODate("2016-08-01T05:35:00.218Z"),
"verifiedOn" : ISODate("2016-08-01T04:35:10.992Z")
},
"mobileID" : {
"isVerified" : true,
"isChecked" : false,
"verificationTokenExpiresIn" : ISODate("2016-08-01T04:42:45.206Z"),
"verifiedOn" : ISODate("2016-08-01T04:33:36.692Z")
}
},
"services" : [
{
"applied" : true,
"appliedOn" : ISODate("2016-09-17T03:01:49.829Z"),
"status" : "Created",
"mac" : "70-77-88-00-AA-BB",
"createdBy" : "Example"
},
]
}
How can I build query, to get student info with the help of mac address 70-77-88-00-AA-BB. i only know mac address value?
i am new here please help me out

Answer 1

Query
services.mac is an array of all the mac addresses members of services
in querying(not in aggregation $eq) an array is equal with a value if it contains that value, so the above will work
the bellow query returns all the students, that have that mac adrress on the services array
if you want to make it fast you can also create an index on "services.mac"
*read mongodb documentation its very good and with examples
Test code here
db.collection.find({
"services.mac": "70-77-88-00-AA-BB"
})