MongoDB Update Operators

db.users.updateOne(
    { name: 'John' },
    { $set: { age: 26, city: 'NYC' } }
); # set field values

db.users.updateOne(
    { name: 'John' },
    { $unset: { age: '' } }
); # remove field

db.products.updateOne(
    { _id: 1 },
    { $inc: { views: 1 } }
); # increment by 1

db.products.updateOne(
    { _id: 1 },
    { $mul: { price: 1.1 } }
); # multiply by 1.1

db.users.updateMany(
    {},
    { $rename: { 'name': 'fullName' } }
); # rename field

db.users.updateOne(
    { name: 'John' },
    { $push: { tags: 'mongodb' } }
); # add to array

db.users.updateOne(
    { name: 'John' },
    { $pull: { tags: 'old-tag' } }
); # remove from array

db.users.updateOne(
    { name: 'John' },
    { $addToSet: { tags: 'mongodb' } }
); # add if not exists