6. Updates, atomic operations, and deletes

In this chapter Updating documents Processing documents atomically Category hierarchies and inventory management

To update is to write to existing documents. But to do this effectively requires a thorough understanding of the kinds of document structures available and of the query expressions made possible by MongoDB. Having studied the e-commerce data model throughout the last two chapters, you should have a good sense for the ways in which schemas are designed and queried. We’ll use all of this knowledge in our study of updates.