https://docs.mongodb.com/manual/reference/mongo-shell/
https://docs.mongodb.com/manual/reference/method/
👆 You really should at leask look at those links
macOS: brew install mongodb or port install mongodb
Linux: Install MongoDB Community Edition on Linux
Docker: mongo
$ mongoList all databases:
show dbs
Switch to database foo:
use foo
List all colections in the database you are currently in:
show collections
List some documents in collection products:
db.products.find()
db.products.find({ price: { $gte: 123 } })
db.products.find({ price: { $gte: 123 } }).pretty()
db.products.find({ price: { $gte: 123 } }).limit(5)
You can convert the results to JS Array:
db.products.find().toArray().filter(doc => doc.stock < doc.min_stock)
When you create an index, do it in the background to not disrupt other clients:
db.persons.createIndex({ name: 1 }, { background: true })
ObjectId is a 12-byte value that consists of: 4-byte timestamp (seconds since Unix epoch), 5-byte random value and 3-byte counter (starting with a random value).
Before mid-2018 it was 3-byte machine identifier and 2-byte process id instead of the 5-byte random value.
How to create ObjectId object:
> ObjectId()
ObjectId("5bf2d543a324d9e1a71aee53")
> ObjectId('123456789012345678901234')
ObjectId("123456789012345678901234")
> ObjectId.fromDate(new Date('2018-11-12T00:00:00Z'))
ObjectId("5be8c2800000000000000000")
Attributes of the ObjectId object:
> ObjectId("507f191e810c19729de860ea").str
507f191e810c19729de860ea
> ObjectId("507f191e810c19729de860ea").valueOf()
507f191e810c19729de860ea
> ObjectId("507f191e810c19729de860ea").getTimestamp()
ISODate("2012-10-17T20:46:22Z")
Show status of replica set:
rs.status()
When you find yourself connected to a secondary but you still want to perform read operations:
rs.slaveOk()
Replica Set Deployment Tutorials
To increase the number of results that you get back from the query (the default is 20):
DBQuery.shellBatchSize = 100;
https://testlio.com/blog/handy-tips-for-mongodb-shell-queries/
http://mo.github.io/2017/01/22/mongo-db-tips-and-tricks.html