mongo db select query

 db.items.find() // ye sari value aur collection ko return karta hai

db.items.find({qty:2323}) // jiski qty 233 hogi usko return karenga .. ye filter ke liye use hota hai 

{qty:2323} ... isko filter object bolte hai

db.items.find({qty:{$gte: 220}}) ... $gte means greater than equal

db.items.find({qty:{$gt: 220}}) ... $gte means greater  than 

$lt = less than 

//or query in mongo db

db.items.find({$or: [{qty:{$gt: 219}},{price:{$gte:122}}]})

// ism khali mujhe name return karenga 

db.items.find({qty:{$gte: 220}},{name:1})

// multiple column return karenga

db.items.find({qty:{$gte: 220}},{name:1,price:1})