MongoDB update()

The MongoDB update() method is a method that is used to update a single document or multiple documents in the collection. When the document is updated the _id field remains unchanged.

The db.collection.update() method updates a single document by default. To update all documents that match the given query, use the multi: true option. Include the option “multi: true“.

Note: In MongoDB, the update() method has been deprecated in favor of using updateOne() or updateMany() depending on your specific use case.

Syntax

db.COLLECTION_NAME.update({SELECTION_CRITERIA}, {$set:{UPDATED_DATA}}, {
     upsert: <boolean>,
     multi: <boolean>,
     writeConcern: <document>,
     collation: <document>,
     arrayFilters: [ <filterdocument1>, ... ],
     hint:  <document|string>        
   })

Explanation: This MongoDB update operation updates documents that match the selection criteria with the specified updated data. Here’s an explanation of the parameters used:

• COLLECTION_NAME: The name of the collection to update.
• SELECTION_CRITERIA: The criteria to select which documents to update.
• UPDATED_DATA: The new data to set for the selected documents.
• upsert: (Optional) If set to true, creates a new document when no document matches the selection criteria.
• multi: (Optional) If set to true, updates multiple documents that match the selection criteria. Default is false, which updates only the first matching document.
• writeConcern: (Optional) Specifies the level of write concern for the operation.
• collation: (Optional) Specifies the collation for string comparisons.
• arrayFilters: (Optional) Filters to determine which elements to modify in an array field.
• hint: (Optional) Forces MongoDB to use a specific index for the operation.

MongoDB update operations allow us to modify documents in a collection. These operations can update a single document or multiple documents based on specified criteria.

MongoDB offers various update operators to perform specific actions like setting a value, incrementing a value or updating elements within arrays. In this article, We will learn about MongoDB update() by understanding various examples in detail.