MongoDB code samples

use db
show collections
show databases
db.mytable.insert({})
db.mytable.find()
db.mytable.find({name:'Ehsan'})
db.mytable.find({name:'Ehsan'},{family:1})
db.mytable.find({name:'Ehsan'},{id:0})
db.mytable.count()
db.mytable.find({name:'Ehsan'}).count()
db.mytable.find({name:'Ehsan'}).skip(1).limit(2)
db.mytable.find({name:'Ehsan'}).sort(name:1) =>asc
db.mytable.find({name:'Ehsan'}).sort(name:-1)=>desc
db.mytable.remove({name:'Ehsan'})
db.mytable.update({name:'Ehsan'},{name:'hassan'}) => removes whole row
db.mytable.update({name:'Ehsan'},{$set:{name:'hassan'}}) => update only this field
db.mytable.update({name:'Ehsan'},{$inc:{age:10}}) => inc this field
db.mytable.update({name:'Ehsan'},{$set:{friends:['me','you']}}) => 
db.mytable.update({name:'Ehsan'},{$push:{friends:'this'}}) => 
db.mytable.update({name:'Ehsan'},{$unset:{friends:1}}) => Removes a field

{"$or":[{imageUrl:''},{tags:''}]}

db.RssLink.find({run_time:{$gt:200, $lt:300}}).count()
db.RssLink.find({$or:[{run_time:{$gt:200}}, {run_time:{$lt:300}}]}).count()
db.RssLink.find({$and:[{run_time:{$gt:200}}, {run_time:{$lt:300}}]}).count()