Joins in KQL

Robert Cain picks back up on a series:

I’m still working on my ArcaneBooks project, mostly documentation, so I thought I’d take a quick break and go back to a few posts on KQL (Kusto Query Language). In this post we’ll cover the join operator.

A join in KQL operates much as it does in SQL. It will join two datasets together into a single result.

Even so, there’s a little more to joins in KQL than in T-SQL, with innerunique being unique to KQL. The closest T-SQL analog would probably be a CROSS APPLY (SELECT TOP(1) ...) operation. KQL also uses join to combine the concepts of EXISTS and NOT EXISTS in SQL.