Sams Teach Yourself SQL in 21 Days, Fourth Edition

Q&A

Q1:	Why are so few functions defined in the ANSI standard and so many defined by the individual implementations?
A1:	ANSI standards are broad strokes and are not meant to drive companies into bankruptcy by forcing all implementations to have dozens of functions. On the other hand, when company X adds a statistical package to its SQL and it sells well, you can bet companies Y and Z will follow suit.
Q2:	I thought you said SQL was simple. Will I really use all of these functions?
A2:	The answer to this question is similar to the answer a trigonometry teacher might give to the question, “Will I ever need to know how to figure the area of an isosceles triangle in real life?” The answer, of course, depends on your profession. The same concept applies ...