John MacKintosh gives us a primer on the COALESCE function in both SQL and R:
What does coalesce mean? In the English language, it is generally used to convey a coming together, or creating one whole body, mass or system. How does that help us when working with data? We spend a lot of time cleaning our data, surely the last thing we want to do is lump it all together?
Click through for detail on the nuances of COALESCE(). H/T R-Bloggers.