Dynamics 365 Web API: How to Perform Multiple POST or Upsert Operations Dynamics 365 Web API: How to Perform Multiple POST or Upsert Operations The Dynamics 365 Web API provides a powerful way to interact with data in a structured and scalable manner. Among its most efficient — yet often underutilized — capabilities is the ability to perform multiple record operations (batch requests) or upserts (insert or update) in a single call. This article walks you through how to correctly build URIs, structure JSON payloads, handle lookup bindings using @odata.bind , and understand how Dynamics 365 interprets and processes these requests internally. 🧩 1. What Is an Upsert Operation? An Upsert is a hybrid between two common database operations: Insert (POST): Creates a new record. Update (PATCH): Updates an existing record. Dynamics 365 automatically determines whether to insert or update based on whether a record with the specified Alternate Key already exists. ...