ksatpute123 (7/25/2013)
Following this I don't see any reason why GROUP BY over aggregate concatenation will not work in any scenario. So far I have never encountered an example of the "undefined". If anyone can post an example precisely explaining this nature mentioned in the KB article then it would be helpful for all.
If you never look when you cross the road "because there are never any cars in this area, and it has always worked for me", you will eventually be run over by a car.
And that is the whole gist of it. Microsoft are not giving you any guarantees that it will work, and thus you should not use it.
Examples? Yes, I have encountered cases where the result was only one of the rows in the result set. Repro? No, this was with older versions of SQL Server.
[font="Times New Roman"]Erland Sommarskog, SQL Server MVP, www.sommarskog.se[/font]