Facing problems to retrieve data using mongodb Pipeline method using Nodejs - node.js

Question

I am facing some problems to crack this particular challenge where I would like to retrieve data from MongoDb using pipeline in Nodejs.
Here is the data from DB:
{
"_id" : ObjectId("623ec44a6900ca5e3a88ece0"),
"student_id" : ObjectId("5fca683c239e4e2693ee20e4"),
"isSession" : true,
"record_list" : [
{
"_id" : ObjectId("623ec4ae319ebd3d243adeb4"),
"Name" : "Adam",
"Type" : 1,
"class_id" : "aa0a2311-5989-4a7b-855f-4c4b73ae6315",
"isPresent" : true
},
{
"_id" : ObjectId("623ec4ae319ebd3d243adeb5"),
"Name" : "Jack",
"Type" : 1,
"class_id" : "fa54389b-4504-465b-9c6c-a386918b8d67",
"isPresent" : true
}
]
}
Here is the output that I expect:
{
"_id" : ObjectId("623ec44a6900ca5e3a88ece0"),
"student_id" : ObjectId("5fca683c239e4e2693ee20e4"),
"isSession" : true,
"record_list" : [
{
"_id" : ObjectId("623ec4ae319ebd3d243adeb5"),
"Name" : "Jack",
"Type" : 1,
"class_id" : "fa54389b-4504-465b-9c6c-a386918b8d67",
"isPresent" : true
}
]
}
I am sending class_id and student_id from UI and based on that it should filter the data and return the entire collection based on these parameters.
controller.ts
let pipeline: any = await Builder.User.SchoolBuilder.studentMatchRecord(payload);
What I tried:
school.builder.ts
export const studentMatchRecord = (payload: any) => {
let pipeline: any = [];
pipeline.push({ $match: { student_id: Types.ObjectId(payload.studentId) } });
pipeline.push(
{ "$unwind": "$record_list" },
{
"$group": {
"record_list.class_id": payload.classId,
}
});
pipeline.push({
$project: {
student_id: 1,
isSession: 1,
record_list: 1,
},
});
return pipeline;
};
and even this:
export const studentMatchRecord = (payload: any) => {
let pipeline: any = [];
let filterConditions: any = { $match: { $and: [] } };
let matchCriteria: any = { $match: { $and: [] } };
matchCriteria.$match.$and.push({
student_id: Types.ObjectId(payload.student_id),
});
if (payload.classId) {
filterConditions.$match.$and.push({
"record_list.class_id": payload.class_id,
});
}
if (filterConditions.$match.$and.length > 0) {
pipeline.push(filterConditions);
}
pipeline.push({
$project: {
student_id: 1,
isSession: 1,
record_list: 1,
},
});
return pipeline;
};
but none of the case is working here. Can you please highlight what am I doing wrong here? Cheers.

Answer 1

Option 1: find/$elemMatch:
db.collection.find({
"student_id": ObjectId("5fca683c239e4e2693ee20e4")
},
{
"record_list": {
"$elemMatch": {
"class_id": "aa0a2311-5989-4a7b-855f-4c4b73ae6315"
}
},
"isSession": 1,
"student_id": 1
})
playground1
Option 2: aggregate/$filter
db.collection.aggregate([
{
$match: {
"student_id": ObjectId("5fca683c239e4e2693ee20e4")
}
},
{
"$addFields": {
"record_list": {
"$filter": {
"input": "$record_list",
"as": "rec",
"cond": {
$eq: [
"$$rec.class_id",
"fa54389b-4504-465b-9c6c-a386918b8d67"
]
}
}
}
}
}
])
playground2