Hibernate: insert into user (id, email, firstname, lastname, password, username) values (default, ?, ?, ?, ?, ?)
2015-12-08 19:10:09.749  WARN 2792 --- [nio-8080-exec-6] o.h.engine.jdbc.spi.SqlExceptionHelper   : SQL Error: -458, SQLState: S1000
2015-12-08 19:10:09.749 ERROR 2792 --- [nio-8080-exec-6] o.h.engine.jdbc.spi.SqlExceptionHelper   : java.lang.NullPointerException
2015-12-08 19:10:09.773 ERROR 2792 --- [nio-8080-exec-6] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.orm.jpa.JpaSystemException: could not execute statement; nested exception is org.hibernate.exception.GenericJDBCException: could not execute statement] with root cause