Tag: KEEP

Getting Top 1 Values Per Group in Oracle

Posted on by lukaseder

I've blogged about generic ways of getting top 1 or top n per category queries before on this blog. An Oracle specific version in that post used the arcane KEEP syntax: SELECT max(actor_id) KEEP (DENSE_RANK FIRST ORDER BY c DESC, actor_id), max(first_name) KEEP (DENSE_RANK FIRST ORDER BY c DESC, actor_id), max(last_name) KEEP (DENSE_RANK FIRST ORDER … Continue reading Getting Top 1 Values Per Group in Oracle →

How to Find the Closest Subset Sum with SQL

Posted on by lukaseder

I've stumbled upon this very interesting question on Stack Overflow, recently. Its title is: [How to] compare a number with sum of subset of numbers In this article, we'll compare the user's imperative approach to the extremely elegant (Oracle) SQL approach. We'll be making use of any combination of these awesome SQL features: Window functions … Continue reading How to Find the Closest Subset Sum with SQL →