Ever tried to recall a SQL function? There's a nifty reference to them in the form of Chapter 4 of "SQL in a Nutshell" available at http://www.oreilly.com/catalog/sqlnut/chapter/ch04.html. It covers Microsoft SQL Server 2000, Oracle 8i, MySQL, and PostgreSQL 7.0.
Another exists at http://www.datadirect-technologies.com/download/docs/jdbc/jdbcref/scalarfn.htm in the form of an appendix regarding the JDBC driver from datadirect. But it lists available functions for DB2, Informix, Oracle, SQL Server, and Sybase.
I've not found a good reference of them in Access. If anyone can recommend one, please let me know.