SQL FOR XML for string concatenation

Just a quick link to a great tip of using the FOR XML clause to concatenate values in rows into a single string (grouped by another column).

These posts go into the mechanics of the FOR XML, and some debate as to the pros and cons.

SQL Merge

I recall a few years ago that the SQL MERGE statement had some problems, and decided that I'd avoid it by just coding its constituent parts (INSERT, UPDATE, DELETE). Today I was wondering if it still had problems, and came across this scoresheet from MSSQLTips. The use cases with problems seem mostly outliers, but there are enough issues that I have trouble feeling confident about the underlying technology. For now, I'll keep coding it by hand.