Chapter 8. Database access

Virtually every significant application uses persistent data in one form or another. The vast majority of them save the data in relational databases. To make it easy to switch from one database to another, Java provides the JDBC^[1] API. While JDBC does handle the required tasks, its low-level nature leads to many lines of code to handle even the simplest tasks.

¹ You would think that JDBC stands for Java Database Connectivity. Everyone would agree with you, except for the people at Sun (now Oracle) who created the API. They claim that JDBC is a trademarked acronym that doesn’t stand for anything. Clearly lawyers were involved somewhere in the process. I’m not going to be bound by such silliness, and if I get sued as a result, I’ll be sure to blog about it.

Because the software is object-oriented and the database is relational, there’s a mismatch at the boundary. The open source Hibernate project attempts to bridge that gap at a higher level of abstraction. Java includes the Java Persistence API (JPA) as a uniform interface to Hibernate and other object-relational mapping (ORM) tools.

8.1. The Java approach, part 1: JDBC

8.2. The Groovy approach, part 1: groovy.sql.Sql

8.3. The Java approach, part 2: Hibernate and JPA

8.4. The Groovy approach, part 2: Groovy and GORM

8.5. Groovy and NoSQL databases

8.6. Summary