use shopping 
db
show dbs 
use shopping1
show dbs
db.dropDatabase()
show dbs
use shopping
db.createCollection("product")
use shopping
show collections
db.createCollection("customers")
show collections
db.customers.drop()
show collections
db.product.insert({productID:1,productname:"laptop",category:"electronics",price:50000,stockquantity:"50"})
db.product.insert({productID:2,productname:"backpack",category:"fashion",price:3000,stockquantity:"75"})
db.product.insert({productID:3,productname:"coffee maker",category:"appliances",price:3000,stockquantity:"75"})
db.product.insert({productID:4,productname:"backpack",category:"fashion",price:3000,stockquantity:"75"})
db.product.find()
db.createCollection("order")
db.order.insert({orderID:1,productID:2,quantity:3})
db.order.insert({orderID:2,productID:4,quantity:2})
db.order.insert({orderID:3,productID:1,quantity:1})
db.order.insert({orderID:4,productID:3,quantity:4})
db.order.find()
db.order.update({orderID:4},{$set:{quantity:5}})
db.order.find()
db.order.update({productID:4},{$set:{stockquantity:25}})
db.product.find()
db.product.find({productID:1})
db.product.find({productname:"bookshelf"})
db.product.find({productID:4},{price:0})
db.product.find({productID:2},{price:1})
db.product.find().pretty()