THE CURIOUS CASE OF THE AGGREGATION QUERY

Summary from the TLDR Web Dev newsletter

This article shows how different SQL database systems execute a peculiar SQL query, which involves subqueries and aggregation functions. Some systems follow the SQL standard and return a single row with the value 6, while others return values 3, 6, and 9 in a table of three rows. The article delves into the SQL standard's specifications regarding aggregation queries, outer references, and historical changes in behavior among different database systems.