MongoDB Examples

examples.js

// FINDING OUR WAY

show dbs
use examples
show collections

// DATA LOADING

function loadData() {
  db.users.insert([
    {
      name: 'john',
      age: 25,
      sections: [ 'news', 'world' ]
    },
    {
      name: 'mary',
      sections: [ 'sports', 'business' ]
    },
    {
      name: 'lucy',
      age: 29
    }
  ])
  print('OK!')
}

loadData()

// INSERT
// db.collection.insert(documents, options)

db.users.insert( { name: 'peter', age: 45 } )
db.users.insert( { name: 'anne', age: 29 } )
db.users.insert( { name: 'bill', age: 32 } )
db.users.insert( { name: 'bob', age: 50 } )
db.users.insert( { name: 'linda', age: 39, sections: [ 'politics' ] } )

// SELECT
// db.collection.find(<criteria>, <projection>)

db.users.find()
db.users.find( { age: { $eq: 29 } } )
db.users.find( { age: { $gt: 25 } } ).sort( { age: -1 } )
db.users.find( { age: { $gt: 25 } } ).sort( { age: -1 } ).limit(3).skip(1)
db.users.find( { age: { $gt: 25 } }, { name: 1 } ).sort( { age: -1 } ).limit(3).skip(1)
db.users.find( { age: { $gt: 25 } }, { sections: 0 } ).sort( { age: -1 } ).limit(3).skip(1)

// UPDATE
// db.collection.update(query, update, options)

db.users.update(
   { },
   { $set: { status: 'A' } }
)
db.users.update(
   { },
   { $set: { status: 'A' } },
   { multi: true }
)
db.users.update(
   { name: { $eq: 'john' } },
   { $set: { sections: [ 'entertainment', 'travel' ] } }
)
db.users.update(
   { name: { $eq: 'john' } },
   { $set: { name: 'john smith' },
     $inc: { age: 10 },
     $push: { sections: 'technology' } }
)

// DELETE
// db.collection.remove(query, options)

db.users.find( { age: { $lt: 35 } } )
db.users.update( { age: { $lt: 35 } }, { $set: { status: 'D' } }, { multi: true }  )
db.users.find( {}, { _id: 0, name: 1, status: 1 } )
db.users.remove( { status: 'D' } )