MongoDB Exercise - A list of restaurants with an 'A' on a specific date

Write a MongoDB query to find the name and address of the restaurants that received a grade of 'A' on a specific date.

Structure of 'restaurants' collection :

{
  "address": {
     "building": "1007",
     "coord": [ -73.856077, 40.848447 ],
     "street": "Morris Park Ave",
     "zipcode": "10462"
  },
  "borough": "Bronx",
  "cuisine": "Bakery",
  "grades": [
     { "date": { "$date": 1393804800000 }, "grade": "A", "score": 2 },
     { "date": { "$date": 1378857600000 }, "grade": "A", "score": 6 },
     { "date": { "$date": 1358985600000 }, "grade": "A", "score": 10 },
     { "date": { "$date": 1322006400000 }, "grade": "A", "score": 9 },
     { "date": { "$date": 1299715200000 }, "grade": "B", "score": 14 }
  ],
  "name": "Morris Park Bake Shop",
  "restaurant_id": "30075445"
}

Query:

db.restaurants.find(
  {
    "grades": {
      "$elemMatch": {
        "date": {
          "$eq": ISODate("2013-07-22T00:00:00Z")
        },
        "grade": {
          "$eq": "A"
        }
      }
    }
  },
  {
    "name": 1,
    "address": 1,
    "_id": 0
  }
)

Output:

  {
address: {
building: '351',
coord: [ -73.98513559999999, 40.7676919 ],
street: 'West   57 Street',
zipcode: '10019'
    },
name: 'Dj Reynolds Pub And Restaurant'
  },
  {
address: {
building: '358',
coord: [ -73.963506, 40.758273 ],
street: 'East 57 Street',
zipcode: '10022'
    },
name: "Neary'S Pub"
  },
  {
address: {
building: '22210',
coord: [ -73.759249, 40.761574 ],
street: 'Northern Boulevard',
zipcode: '11361'
    },
name: 'Burger King'
  },
.....

Explanation:

The said query in MongoDB retrieves the name and address fields of all documents from the 'restaurants' collection that have at least one "grades" sub-document containing a specific date and grade.

The "date": { "$eq": ISODate("2013-07-22T00:00:00Z") } condition checks within the $elemMatch operator if any of the grades have a date equal to 2013-07-22 and the "grade": { "$eq": "A" } condition checks if any of the grades have a grade equal to 'A'.

The date have used in the ISODate format which is similar to date in the restaurants collection.

Note: This output is generated using MongoDB server version 3.6

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