> Learn SQL Once, Use It for 30 Years.
Well, during those 30 years you'd have to learn a few additions that were added to the SQL standard, like "OVER / PARTITION BY", and maybe a few non-standard extensions like "QUALIFY".
There have been 11 modifications to the SQL standard since the initial SQL-86 ANSI standard of 1986.
Very worthwhile additions in most cases IMO, and well worth the "continued education" required.