Finding Documents by Using Logical Operators

Review the following logical operators: implicit $and, $or, and $and.

Find a Document by Using Implicit $and

Use implicit $and to select documents that match multiple expressions. For example:

db.routes.find({ "airline.name": "Southwest Airlines", stops: { $gte: 1 } })

Find a Document by Using the $or Operator

Use the $or operator to select documents that match at least one of the included expressions. For example:

db.routes.find({
  $or: [{ dst_airport: "SEA" }, { src_airport: "SEA" }],
})

Find a Document by Using the $and Operator

Use the $and operator to use multiple $or expressions in your query.

db.routes.find({
  $and: [
    { $or: [{ dst_airport: "SEA" }, { src_airport: "SEA" }] },
    { $or: [{ "airline.name": "American Airlines" }, { airplane: 320 }] },
  ]
})