use salesDB
show db
db.createCollection("book")
db.book.insertOne({
    name:"abc",
    author:"jay"
}) 

db.book.insertMany([
    {
        name:"xyz",
        author:"ram",
        year:2678
    
},
    {
        name:"hgs",
            author:"reva",
            yera:678
    }
    
])

db.book.find();

db.book.find({
    year:{$gt :2000}
})

db.book.find({
    id:1
})


db.book.insertMany([{

    name:"anu",
    author:"anu",
    year:2021
},
                    
                    {
    name:"anu1",
    author:"anu1",
    year:2011
}
 ])




//Update a Single Document
db.book.updateOne(
    { name:"hgs"},
    { $set:{yera:2026}}
)

db.book.find(
    { yera:2026}
)

db.book.updateMany(
    { year:{$lt:2021}},
      {$set:{author:"anuradha"}} )


db.book.find(
    {
        year:{$lte:2021}
    }
)
db.book.find()
db.book.deleteOne(
    {name:"jay"}
)