text: create table USER (
  	ID identity primary key,
  	NAME varchar not null,
  	VERSION BIGINT,
  	CREATED_DATE TIMESTAMP,
  	LAST_MODIFIED_DATE TIMESTAMP,
  	CREATED_BY_ID BIGINT,
  	LAST_MODIFIED_BY_ID BIGINT,
  	constraint USER_CREATED_BY_USER foreign key (CREATED_BY_ID) references USER (ID),
  	constraint USER_LAST_MODIFIED_BY_USER foreign key (LAST_MODIFIED_BY_ID) references USER (ID)
  );
  
  create table CUSTOMER (
  	ID identity primary key,
  	FIRST_NAME varchar not null,
  	LAST_NAME varchar not null,
  	CREATED_DATE TIMESTAMP,
  	LAST_MODIFIED_DATE TIMESTAMP,
  	CREATED_BY_ID BIGINT,
  	LAST_MODIFIED_BY_ID BIGINT,
  	constraint CUS_CREATED_BY_USER foreign key (CREATED_BY_ID) references USER (ID),
  	constraint CUS_LAST_MODIFIED_BY_USER foreign key (LAST_MODIFIED_BY_ID) references USER (ID)
  );
  
  