A lot of people don't consider SQL programming. Usually we think of more traditional programming languages, but SQL is at the root of most information systems. A lot of programmers don't know SQL, it can be difficult -- it is difficult.
But I believe it to be the most powerful programming concept you can learn, simply due to the answers it can help you find.
you can make sql-like data management using programming languages (see practical common lisp ch 3); however, you can't use sql alone to accomplish what languages can
sql is very limiting ... to me, that's enough to justify not investing more time in sql
But I believe it to be the most powerful programming concept you can learn, simply due to the answers it can help you find.