JPA-SQL is a domain-specific, database-independent language (DSL). The syntax is deliberately similar to SQL so that JPA-SQL is easy to learn. However, JPA-SQL is not to be confused with native SQL. Queries formulated in JPA-SQL are never sent to a database. Instead, they are converted to Java code based on the JPA Criteria API. Thus, you can access all the benefits of the JPA Criteria API without having to write the JPA Criteria code.

At runtime, the JPA provider generates the native SQL statements from the generated JPA Criteria code to match the connected database, and these are sent to the database. Thus JPA-SQL combines the simplicity of SQL with the numerous advantages of JPA Criteria API.

JPA-SQL Documentation