MongoDB : lookup exact match without false rows - mongodb

Question

I have 3 tables :
accounts:[
{id:111,name:'john'},
{id:222,name:'due'}
]
workoutTypes:[
{id:1,title:'a'},
{id:2,title:'b'}
]
accountrecords:[
{_id:10,workoutTypeId:1,accountId:111},
{_id:11,workoutTypeId:1,accountId:222}
]
I used this command to group all account records by workout type that match to the current account like that:
db.workoutTypes.aggregate([
{
$lookup: {
from: "accountrecords",
localField: "_id",
foreignField: "workoutTypeId",
as: "records"
}
},
{
$match: {
$and: [
{ "records": { $ne: [] } },
{ "records.accountId": { $eq: mongoose.Types.ObjectId(accountId) } },
]
}
},
])
the issue that I'm getting the records that related to both of accounts.
saw that eq command return a false value for non-match values.
there is an option to get only the record that matches to current account?

Answer 1

First of all your localField on workoutTypes collection must be id, not _id. Probably a typo from your side. Secondly, you need to use $redact operator if you want to restrict the content. $match actually works as expected, but it actually isn't checking whether all your sub documents are satisfying the criteria.
Update:
Try this query:
db.workoutTypes.aggregate([
{
$lookup: {
from: "accountrecords",
localField: "_id",
foreignField: "workoutTypeId",
as: "records"
}
},
{$match:{"records.accountId":{$exists:true}, "records.accountId":{$eq:ObjectId("5a604b18280420c03e8d3a23")}}},
{$redact:{
$cond:{
if:{$or:[{$eq:["$accountId",ObjectId("5a604b18280420c03e8d3a23")]},{$not:"$accountId"}]},
then:"$$DESCEND",
else:"$$PRUNE"
}
}}
])
And the output is:
/* 1 */
{
"_id" : ObjectId("5ac8b2b8fb45830ff77cd33b"),
"updatedAt" : ISODate("2018-04-07T11:59:52.583Z"),
"createdAt" : ISODate("2018-04-07T11:59:52.583Z"),
"title" : "Snatch",
"__v" : 0,
"records" : [
{
"_id" : ObjectId("5acb1b666b08493b30deed92"),
"updatedAt" : ISODate("2018-04-09T07:51:02.294Z"),
"createdAt" : ISODate("2018-04-09T07:51:02.294Z"),
"accountId" : ObjectId("5a604b18280420c03e8d3a23"),
"workoutTypeId" : ObjectId("5ac8b2b8fb45830ff77cd33b"),
"repetition" : 4,
"weight" : 120,
"__v" : 0
},
{
"_id" : ObjectId("5acb1b6f6b08493b30deed93"),
"updatedAt" : ISODate("2018-04-09T07:51:11.878Z"),
"createdAt" : ISODate("2018-04-09T07:51:11.878Z"),
"accountId" : ObjectId("5a604b18280420c03e8d3a23"),
"workoutTypeId" : ObjectId("5ac8b2b8fb45830ff77cd33b"),
"repetition" : 5,
"weight" : 130,
"__v" : 0
},
{
"_id" : ObjectId("5ace23aa1c4d590dc049e94e"),
"updatedAt" : ISODate("2018-04-11T15:03:06.824Z"),
"createdAt" : ISODate("2018-04-11T15:03:06.824Z"),
"repetition" : 124,
"weight" : 32,
"accountId" : ObjectId("5a604b18280420c03e8d3a23"),
"workoutTypeId" : ObjectId("5ac8b2b8fb45830ff77cd33b"),
"__v" : 0
},
{
"_id" : ObjectId("5ace23b21c4d590dc049e94f"),
"updatedAt" : ISODate("2018-04-11T15:03:14.293Z"),
"createdAt" : ISODate("2018-04-11T15:03:14.293Z"),
"repetition" : 325,
"weight" : 235,
"accountId" : ObjectId("5a604b18280420c03e8d3a23"),
"workoutTypeId" : ObjectId("5ac8b2b8fb45830ff77cd33b"),
"__v" : 0
},
{
"_id" : ObjectId("5acc8ef5345125417cca18e3"),
"updatedAt" : ISODate("2018-04-10T10:16:21.709Z"),
"createdAt" : ISODate("2018-04-10T10:16:21.709Z"),
"repetition" : 123,
"weight" : 456,
"accountId" : ObjectId("5a604b18280420c03e8d3a23"),
"workoutTypeId" : ObjectId("5ac8b2b8fb45830ff77cd33b"),
"__v" : 0
}
]
}
/* 2 */
{
"_id" : ObjectId("5acdf56afd5ca008d01b706f"),
"updatedAt" : ISODate("2018-04-11T11:45:46.192Z"),
"createdAt" : ISODate("2018-04-11T11:45:46.192Z"),
"title" : "Jerk",
"__v" : 0,
"records" : [
{
"_id" : ObjectId("5acdf597fd5ca008d01b7070"),
"updatedAt" : ISODate("2018-04-11T11:46:31.674Z"),
"createdAt" : ISODate("2018-04-11T11:46:31.674Z"),
"repetition" : 12,
"weight" : 100,
"accountId" : ObjectId("5a604b18280420c03e8d3a23"),
"workoutTypeId" : ObjectId("5acdf56afd5ca008d01b706f"),
"__v" : 0
}
]
}
/* 3 */
{
"_id" : ObjectId("5ace336ed36c780e6ce76d5d"),
"updatedAt" : ISODate("2018-04-11T16:10:22.483Z"),
"createdAt" : ISODate("2018-04-11T16:10:22.483Z"),
"title" : "Weight lifting",
"__v" : 0,
"records" : [
{
"_id" : ObjectId("5ace337ed36c780e6ce76d5e"),
"updatedAt" : ISODate("2018-04-11T16:10:38.708Z"),
"createdAt" : ISODate("2018-04-11T16:10:38.708Z"),
"repetition" : 21,
"weight" : 100,
"accountId" : ObjectId("5a604b18280420c03e8d3a23"),
"workoutTypeId" : ObjectId("5ace336ed36c780e6ce76d5d"),
"__v" : 0
}
]
}
/* 4 */
{
"_id" : ObjectId("5ac8cf5ef14469169d8627e8"),
"updatedAt" : ISODate("2018-04-07T14:02:06.155Z"),
"createdAt" : ISODate("2018-04-07T14:02:06.155Z"),
"title" : "Double under",
"__v" : 0,
"records" : [
{
"_id" : ObjectId("5acc8f11345125417cca18e4"),
"updatedAt" : ISODate("2018-04-10T10:16:49.069Z"),
"createdAt" : ISODate("2018-04-10T10:16:49.069Z"),
"repetition" : 111111,
"weight" : 222222,
"accountId" : ObjectId("5a604b18280420c03e8d3a23"),
"workoutTypeId" : ObjectId("5ac8cf5ef14469169d8627e8"),
"__v" : 0
},
{
"_id" : ObjectId("5ace2d7b1c4d590dc049e950"),
"updatedAt" : ISODate("2018-04-11T15:44:59.722Z"),
"createdAt" : ISODate("2018-04-11T15:44:59.722Z"),
"weight" : 23,
"repetition" : 123555555,
"accountId" : ObjectId("5a604b18280420c03e8d3a23"),
"workoutTypeId" : ObjectId("5ac8cf5ef14469169d8627e8"),
"__v" : 0
}
]
}
/* 5 */
{
"_id" : ObjectId("5ac8cfdd79a48216b3e048b0"),
"updatedAt" : ISODate("2018-04-07T14:04:13.670Z"),
"createdAt" : ISODate("2018-04-07T14:04:13.670Z"),
"title" : "Push-ups",
"__v" : 0,
"records" : [
{
"_id" : ObjectId("5accc1f1cd58a407c6562f79"),
"updatedAt" : ISODate("2018-04-10T13:53:53.933Z"),
"createdAt" : ISODate("2018-04-10T13:53:53.933Z"),
"repetition" : 123,
"weight" : 456000,
"accountId" : ObjectId("5a604b18280420c03e8d3a23"),
"workoutTypeId" : ObjectId("5ac8cfdd79a48216b3e048b0"),
"__v" : 0
}
]
}
Now you just replace ObjectId("5a604b18280420c03e8d3a23") in the query with your mongoose code mongoose.Types.ObjectId(accountId) and you should be good now.