I learned SQL at a local college using a small SQL book, it had a baby blue hard cover, and was probably around 100-150 pages. It was in 1992 or 1993 that I took the course.
It was, as I recall, not related to any specific SQL tool - very generic.
It did a great job of explaining the basics and I really wish I could find it again.
EDIT
I think this is the book:
SQL, Structured Query Language
Carolyn J. Hursch, Jack L. Hursch
However, I can't find an image to be sure... still looking...
The best I can think of is to search here on Google Books for it. You may be able to identify it better than I. I hope this helps you find it.
EDIT:
How about this? Another Google Book Link
They speak of Hursch and Hursch 1988 SEQUEL (which was a forerunner to SQL I believe) IBM stuff. This is beginning to look promising.
1988: Hursch and Hursch? Found something else at: http://tinyurl.com/6q2bac
That more closely reflects what you've remembered the title to be.
Newer editions might have increased the number of pages and changed the front page. Any chance this is what you are looking for?
Select Sql: The Relational Database Language
Update: One more try :) SQL (Visual QuickStart Guide)