How does mongodb update() method work?

@hal.littel 

The update() method in MongoDB is used to update documents in a collection. It takes two main parameters: a query parameter that specifies the selection criteria for the documents to be updated, and a update parameter that specifies the modifications to be made to the documents that match the query criteria.

The syntax of the update() method is as follows:

db.collection.update(query, update)

The query parameter is similar to the find() method and specifies the selection criteria for the documents to be updated. The update parameter includes the modifications to be made to the matched documents.

There are several options that can be used with the update() method to control how the update operation is applied, such as upsert, multi, and write concern options.

The upsert option can be used to insert a new document if no documents match the query criteria. The multi option can be used to update multiple documents that match the query criteria. The write concern option can be used to control the level of acknowledgment required for the update operation.

Overall, the update() method in MongoDB provides a flexible way to update documents in a collection based on specified criteria and modifications.