What if I don like the SQL TopLink generates for queries?
Queries can be specified directly in SQL if the SQL generated by TopLink for Expression or EJBQL based queries is unacceptable. However, this is not typically necessary. The SQL generated by TopLink for reading, writing, and deleting objects based on a class’s descriptor can also be overridden. Refer to SQL Queries and Configuring Custom SQL Queries for Basic Persistence Operations in the Oracle TopLink Developer’s Guide for more information.