PG Phriday: PostgreSQL Select Filters
Long have CASE statements been a double-edged sword in the database world. They’re functional, diverse, adaptive, and simple. Unfortunately they’re also somewhat bulky, and when it comes to using them to categorize aggregates, something of a hack. This is why I wanted to cry with joy when I found out that PostgreSQL 9.4 introduced a feature I’ve always wanted, but found difficult to express as a need. I mean, CASE statements are fine, right? Well, yes they are, but now we have something better. Now, we have the FILTER aggregate expression.