MongoDB Update Operators:

 MongoDB provides several update operators that allow you to modify documents in a collection. These operators offer flexible and powerful ways to update specific fields or elements within documents. Here are some commonly used update operators in MongoDB:


$set: Sets the value of a field in a document. If the field doesn't exist, it creates it.

  1. Example:
db.collection.updateOne({ _id: ObjectId("123") }, { $set: { name: "John" } })




$unset: Removes a field from a document.

  1. Example:
db.collection.updateOne({ _id: ObjectId("123") }, { $unset: { age: "" } })




$inc: Increments the value of a field by a specified amount.

  1. Example:
db.collection.updateOne({ _id: ObjectId("123") }, { $inc: { score: 10 } })




$mul: Multiplies the value of a field by a specified amount.

  1. Example:
db.collection.updateOne({ _id: ObjectId("123") }, { $mul: { price: 1.1 } })




$rename: Renames a field.

  1. Example:
db.collection.updateOne({ _id: ObjectId("123") }, { $rename: { "oldField": "ne




$push: Adds an element to an array field.

  1. Example:
db.collection.updateOne({ _id: ObjectId("123") }, { $push: { scores: 85 } })



$pop: Removes the first or last element from an array field.

  1. Example:
db.collection.updateOne({ _id: ObjectId("123") }, { $pop: { scores: 1 } }) // Removes the last element 
db.collection.updateOne({ _id: ObjectId("123") }, { $pop: { scores: -1 } }) //Removes the last element 



$addToSet: Adds an element to an array field only if it doesn't already exist.

  1. Example:
db.collection.updateOne({ _id: ObjectId("123") }, { $addToSet: { tags: "newTag"




$pull: Removes all instances of a specified value from an array field.

  1. Example:
db.collection.updateOne({ _id: ObjectId("123") }, { $pull: { tags: "oldTag" } })

These are just a few examples of the update operators available in MongoDB. You can use multiple operators together in a single update operation to perform complex updates on documents in a collection.