Java Database Connectivity (JDBC) and SQLJ are important topics relevant to Enterprise Information Systems (EIS), whether it be Legacy or middleware. JDBC is analogous to ODBC. SQLJ is a Java optimized query language specification, currently under review.
J D B C - A Persistant Storage for Java Objects
Build data-type-independent JDBC applications
Using JDBC in Servlet I - Simple Book Query
How to Use Java and JDBC To Access a Database
Using ODBC-JDBC with java.sql.*
Use Microsoft Access with Java - How do you connect to an Access-based database with JDBC?
JDBC drivers in the wild - Learn how to deploy, use, and benchmark JDBC driver types 1, 2, 3, and 4
JDBC usage for industrial-strength performance
Optimize a query on a Map - Comparing techniques for performance tuning a query on a Map class