mongodb find all documents with common value

Question

How can I find all the documents with a common 'category'?

Below are my sample documents. How can get the documents that are common in categories?

{
    "_id": {
        "$oid": "59b7fcace893d0450c44ada3"
    },
    "title": "Tesla model 3 questions",
    "category": "movie",
    "questionAndAnswers": '',
    "__v": 0
}
{
    "_id": {
        "$oid": "59c4e12fd5276138f41c0896"
    },
    "title": "SpaceX Quiz",
    "category": "Science",
    "questionAndAnswers": '',
"__v": 0
}
{
    "_id": {
        "$oid": "59c4e12fd5276138f41c0890"
    },
    "title": "Nasa Quiz",
    "category": "Science",
    "questionAndAnswers": '',
"__v": 0
}

Answer 1

db.collection.find({"category": "Science"}) will return a cursor, which you can iterate to get all the documents where "category" is "Science".

Check - https://docs.mongodb.com/manual/reference/method/db.collection.find/#find-documents-that-match-query-criteria

Answer 2

Simply use where category == 'theCommonCategory'.

It will give you all the documents that have theCommonCategory.