2 posts tagged with "upsert"

A while I ago I covered the upsert feature PostgreSQL introduced with version 9.5. Back then I showed you how to make use of upsert with one field - the primary key - as conflict target. In a recent attempt to modify the upsert logic to take 2 fields into account I tried to add the additional field to the conflict target:

Since version 9.5 PostgreSQL provides support for upsert. Upsert allows you to "atomically either insert a row, or on the basis of the row already existing, UPDATE that existing row instead, while safely giving little to no further thought to concurrency". While experimenting with the Prooph Event Store library I came across a good use-case for upsert, so I gave it a try. The goal was to build a projection based on the event stream to count the number certain events based for a specific day - think of registrations per day.