CREATE TABLE "USER"
  (
    USER_ID          NUMBER(10) NOT NULL,
    CREATOR_USER_FK  NUMBER(10) NOT NULL,
    ...
    PRIMARY KEY (USER_ID)
  );
CREATE SEQUENCE SEQ_USER START WITH 1 INCREMENT BY 1;
CREATE TRIGGER "USER_ID_SEQ_INC" BEFORE
  INSERT ON "USER" FOR EACH ROW BEGIN
  SELECT SEQ_USER.nextval
  INTO :new.USER_ID
  FROM DUAL;
END;

...
<jdbc:initialize-database data-source="dataSource"
    ignore-failures="DROPS" enabled="${jdbc.enableSqlScripts}">
    <jdbc:script location="${jdbc.initLocation}" />
    <jdbc:script location="${jdbc.dataLocation}" />
</jdbc:initialize-database>
...

DROP SEQUENCE SEQ_USER;
DROP TABLE "USER" CASCADE CONSTRAINTS;
PURGE TABLE "USER";
CREATE TABLE "USER"
  (
    USER_ID          NUMBER(10) NOT NULL,
    CREATOR_USER_FK  NUMBER(10) NOT NULL,
    PRIMARY KEY (USER_ID)
  );
ALTER TABLE "USER" ADD CONSTRAINT FK_USER_CUSER FOREIGN KEY (CREATOR_USER_FK) REFERENCES "USER" (USER_ID);
CREATE SEQUENCE SEQ_USER START WITH 1 INCREMENT BY 1;
CREATE TRIGGER "USER_ID_SEQ_INC" BEFORE
  INSERT ON "USER" FOR EACH ROW
  WHEN (new.USER_ID IS NULL)
BEGIN
  SELECT SEQ_USER.nextval
  INTO :new.USER_ID
  FROM DUAL;
END;
/
ALTER TRIGGER "USER_ID_SEQ_INC" ENABLE;

@Before
public void executeSomeSql() {
    Connection c;
    try {
        c = dataSource.getConnection();
        c.createStatement()
                .execute("CREATE TABLE "USER" (USER_ID NUMBER(10) NOT NULL, CREATOR_USER_FK NUMBER(10) NOT NULL, PRIMARY KEY (USER_ID))");
        c.createStatement()
                .execute("CREATE SEQUENCE SEQ_USER START WITH 1 INCREMENT BY 1");
        c.createStatement()
                .execute("CREATE OR REPLACE TRIGGER "USER_ID_SEQ_INC" BEFORE INSERT ON "USER" FOR EACH ROW WHEN (new.USER_ID IS NULL) BEGIN SELECT SEQ_USER.nextval INTO :new.USER_ID FROM DUAL; END;");
    } catch (SQLException e) {
        logger.debug(e);
    }
}