ok, looking at programming language pragmatics it seems like you want fairly serious (university level) theory. so i don't understand why people are talking about regexps - that should be covered in a subsection (regular grammars) of one chapter of that book.

anyway, for databases i would suggest date's "sql and relational theory" - it shows how sql is related to a more elegant, cleaner, underlying theoretical approach and will get you to think in more declarative terms.

for general programming, sicp is worth reading if you haven't read it already.

for algorithms, either (or both - they are very different) cormen et al (lots of tedious detail - you need to choose which bits to read) or the algorithm design manual http://www.algorist.com/

you don't ask about numerical work, but for anyone interested, gershenfeld's "nature of mathematical modelling" is concise, broad, and has some very deep insights (the few pages on wavelets are the best i have read anywhere).

for security, scheneier's applied crypto is a pretty good intro (again, skip some bits, and remember it's old). and anderson's "security engineering" is the other classic (which i should read...).

for ai (again, you didn't ask) both norvig's books are good (the more modern one is aimed at modern statistical approaches that work, but the older one has a lot of good basic programming and lisp).