How to retrieve the unique records from mongodb

user_14724891 0
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I am facing a bit of difficulty in the writing a mongodb query actually, tried various queries but one seems to be working out.

I have a db of records of the similar one, i need to retrieve a the documents based on priority.

Records

[
  {name :"abc", age:"45",gender:"male", interests :"sports"},
  {name :"xyz", age:"60",gender:"male", interests :"books"}
  {name :"abc", age:"45",gender:"male" interests :"books"},
  {name :"qwerty", age:"15",gender:"female" interests :"sports"}
]

Expected Output

[
  {name :"abc", age:"45", interests :"sports"},
  {name :"xyz", age:"60", interests :"books"}
]

the output of db query should be based on priority

Explanation: I need to retrive the records of gender male, and when looking for interests if a user has interest on sports, we should ignore the record of books for that user, but if a user doesn't have a record on sports, we need to return the record matching books.

I wrote a aggregation query, but not fitting my expectation so looking for alternatives.

mongoose aggregation-framework mongodb-query mongodb
1 Answers

Let me Help you with a suggestion -

[{$match: {
  gender: "male",
}}, {$group: {
  _id: "$name",
  age: {$first: "$age"},
  gender: {$first: "$gender"},
  interests: {$push: "$interests"},
}}, {$project: {
  name: "$name",
  age: "$age",
  gender: "$gender",
  interests: {
    $cond: {
      if: {"$in": ["sports", "$interests"]},
      then: "sports",
      else: "books" 
    }
  }
}}]
user_46968970
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