CRUD

Start MongoDB in cmd -> mongo

Show all databases -> show dbs

Select/Create database -> use <DB name>
 > use circus

Show all collections in a database -> show collections

Create collection -> db.createCollection(<name in quotes>)
 > db.createCollection("clowns")



---------[C] R U D----------

Create one document ->  db.<collection_name>.insertOne(<field and values in curlies>)
 >  db.clowns.insertOne({name:"Puspendu", skill:"blabbering", salary:12000, partner:"Aditi", required:true})

Create many documents -> db.<collection_name>.insertMany([<field and values in curlies>, <field and values in curlies>, ...])
 >  db.clowns.insertMany([{name:"Prianshu", skill:"coding", salary:50000, partner:"Priyanka", required:true}, {name:"Sankhadip", skill:"running"}])



---------C [R] U D----------

Read docs from a collection -> db.<collection_name>.find(<condition in curlies>, <projection in curlies>).pretty()
 >  db.clowns.find().pretty()
 >  db.clowns.find({name:"Sankhadip"}, {}).pretty()
 >  db.clowns.find( {},{_id:0, name:1}).pretty()
 >  db.clowns.find( {salary:{$gt:13000}}, {_id:0, name:1}).pretty()
 >  db.clowns.find( {salary:{$exists:false}}, {_id:0, name:1}).pretty()



---------C R [U] D----------

Update one document -> db.<collection_name>.updateOne(<selection condition>, <set field values>)
 > db.clowns.updateOne({name:"Sankhadip"}, {$set:{partner:"Uber Kaku"}})
 > db.clowns.updateOne({name:"Puspendu"}, {$set:{partner:"Soumya Sen", skill:"BIZNEZZ"})

Update many documents -> db.<collection_name>.updateMany(<selection condition>, <set field values>)
 > db.clowns.updateMany({salary:{$gt:20000}}, {$set:{required:false}})

Replace one document -> db.<col_name>.replaceOne(<selection condition>, <new fields and values>)
 > db.animals.replaceOne({name:"Pratim"}, {name:"Bawaseer", type:"Ape", habitat:"South Calcutta"})




---------C R U [D]----------


Delete one document -> db.<col_name>.deleteOne(<selection condition>)
 > db.animals.deleteOne({name:"Sayantan"})
 > db.animals.deleteOne({})		\\Delete 1st one


Delete many document -> db.<col_name>.deleteMany(<selection condition>)
 > db.animals.deleteMany({skill:"Office Work"})
 > db.animals.deleteMany({})		\\Delete all




-------------Extra Stuff----------------

Drop collection -> db.<col_name>.drop()
 > db.tax_records.drop()

Delete database -> db.dropDatabase()