disclaimer: I'm using SQL just for learning / pain fun ATM. I developed a simple api using next.jdbc and postgres Then I tryied to run it over hsqldb . I thought that hsqldb would throw something like cannot create table: "TEXT" is not a data type but it throws really odd things There is some guidelines/method about "how to write plataform agnostic SQL"? Maybe something also related to jdbc.

DDL -- creating takes etc -- is notoriously DB-specific but you can wrote a lot of SQL that is portable.

Take a look at the tests for both next.jdbc and clojure.java.jdbc as they both contain conditional logic to work across multiple databases.