MongoDB first steps

db.createUser({

  user: "admin",

  pwd: "admin",

  roles: ["readWrite","dbAdmin"]

});

db.createCollection('customers');

show collections

db.customers.insert({first_name: "Ivan", last_name: "Ivanov"});

db.customers.find();

db.customers.insert([

  {first_name: "Ivan1", last_name: "Ivanov1"},

  {first_name: "Ivan2", last_name: "Ivanov2"},

  {first_name: "Ivan3", last_name: "Ivanov3", gender:"male"},

]);

db.customers.find().pretty();

//Update only the first match for the key and replace all the values (if not set will remove the old one)

db.customers.update({first_name: "Ivan2"}, {last_name: "222"});

//$set will keep the previous values and add the new one

db.customers.update({first_name: "Ivan2"}, {$set:{age: 45}});

//will increment with 5 the age value

db.customers.update({first_name: "Ivan2"}, {$inc:{age: 5}});

db.customers.update({first_name: "Ivan2"}, {$unset:{age: 1}});

//if not found, insert it

db.customers.update(

  {first_name: "Mariyka"}, 

  {first_name: "Mariyka", last_name: "Mariykova", gender:"female"},

  {upsert: true}

);

//rename field

db.customers.update({first_name: "Ivan2"}, {$rename:{"gender":"sex"}});

db.customers.remove({last_name: "222"});

db.customers.remove({last_name: "222"},{justOne:true});

db.customers.find({first_name: "Ivan"});

db.customers.find({$or:[{first_name: "Ivan"},{first_name: "Mariyka"}]});

//greater than ($gt)

db.customers.find({age:{$gt:40}}).pretty();

db.customers.find({"address.city":"Varna"}).pretty();

db.customers.find().sort({last_name:1}).pretty();

db.customers.find({gender:"male"}).count();

db.customers.find().limit(2);

db.customers.find().forEach(function(doc){print("Customer name: "+doc.first_name)});