CODEWITHSUNDEEP
arraysmongodbaggregation-framework
user3470294
user3470294

Reputation: 190

MongoDB - match id of a collection with the given array

I have a student collection like below,

{_id:22222, student_id:1}
{_id:22223, student_id:2}
{_id:22224, student_id:3}
{_id:22225, student_id:4}

I have an array like [1,2], and I want to return only the documents that as the same student_id in the array.

if the array is [1,3], the output should be also in an array [1,3]

if I have array like [4,7], and since 7 is not a valid student_id, it should return only [4]

Upvotes: 0

Views: 41

Answers (2)

Mahesh Bhatnagar
Mahesh Bhatnagar

Reputation: 1080

Use with aggregate with match keyword

db.Signal.aggregate(
  {$match:{student_id:{$in:[4,3]}}},
  {$project:{_id:0,'student_id':1}},
  { $group: { _id: null, student: { $push:'$student_id' } } }
)

Upvotes: 1

Wernfried Domscheit
Wernfried Domscheit

Reputation: 59557

Use the $in operator:

db.students.find({
   student_id: { $in: [1, 7] }
})

Upvotes: 1

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