SQLUnit is a regression and unit testing harness for testing database stored procedures. The test suite is written as an XML file. The SQLUnit harness itself is written in Java and uses the JUnit unit testing framework to convert the XML test specifications to JDBC calls and compare the results generated from the calls with the specified results.
Stored procedures are often used to provide an object abstraction to the underlying relational data store. The object abstractions are consumed by Java middleware programs. In shops where this is the case, Java programmers often use the popular JUnit testing framework to unit test their code. Using SQLUnit to unit test the database stored procedures thus becomes a natural extension of the unit testing process, and provides unit testing coverage for a layer that is often neglected in this respect.
Since the stored procedure author need not be a Java coder, and may not even know Java or JUnit, SQLUnit provides an XML language to write test suites. Stored Procedure authors who know Java and/or can write JUnit tests will find that the repetitive nature of JDBC programming would, over time, encourage refactoring the common parts of the tests into utility classes. SQLUnit already does this, except it goes one step further and abstracts the test specification out of Java into XML.
The XML itself is fairly small and easy to learn for anybody and should be instantly intuitive to a person who is already familiar with JUnit.
Further, since SQLUnit uses JDBC to communicate with the database, it should be possible to write unit tests for stored procedures for any database that provides a JDBC driver. Some relatively painless porting may be needed for each new DBMS or driver, due to vendor-specific extensions to the SQL standard or restrictions of the JDBC API.