![The COALESCE function: PROC SQL compared with PROC IML](https://blogs.sas.com/content/iml/files/2011/05/t_coalesce.png)
When Charlie H. posted an interesting article titled "Top 10 most powerful functions for PROC SQL," there was one item on his list that was unfamiliar: the COALESCE function. (Edit: Charlie's blog no longer exists. The article used to be available at http://www.sasanalysis.com/2011/01/top-10-most-powerful-functions-for-proc.html) Ever since I posted my first response,