1.
let count = db.restaurants.countDocuments({
  "cuisine": "Italian",
  "grades.score": { $gte: 10 }
});

print(count);

db.restaurants.find(
  {
    "cuisine": "Italian",
    "grades.score": { $gte: 10 }
  },
  {
    name: 1,
    "grades.score": 1,
    "address.coord": 1,
    _id: 0
  }
).sort({ name: -1 });


2.
let count = db.restaurants.find(
  {
    "note": "A",
    "grades.score": { $gte: 20 }
  },
  {
    name: 1,
    _id: 0
  }
).count();

print(count);

db.restaurants.find(
  {
    "note": "A",
    "grades.score": { $gte: 20 }
  },
  {
    name: 1,
    _id: 0  
  }
).sort(
  { name: -1 }
)


3.
db.restaurants.distinct("borough");


4.
db.restaurants.find({ "borough": "Bronx" });


5.
db.restaurants.find({
  "borough": "Bronx",
  $expr: {
    $eq: [
      { $size: "$grades" },
      4
    ]
  }
});


6.
db.restaurants.find({
  "borough": "Bronx",
  $or: [
    { "grades.grade": "A" },
    { "grades.grade": "B" }
  ]
});


7.
db.restaurants.find({
  "borough": "Bronx",
  $or: [
    { "grades.0.grade": "A" },
    { "grades.0.grade": "B" }
  ]
});


8.
db.restaurants.find({
  name: { $regex: /[cC]offee/ }
})


9.
db.restaurants.find({
  borough: "Bronx",
  name: { $regex: /coffee/i }
})


10.db.restaurants.find({
  name: {
    $regex: /Coffee|Restaurant/i
  },
  name: {
    $not: /Starbucks/i
  }
})


11.
db.restaurants.find({
  name: { $regex: /coffee/i },
  borough: { $in: ["Bronx", "Brooklyn"] },
  grades: { $size: 4 }
})


12.
db.restaurants.find({
  name: {
    $regex: /^(?=.*[aeiouAEIOU]$)[aeiouAEIOU].*/, 
    $options: "i"
  }
})