A quick JPA + Oracle sequences example, for self reference.

1. Oracle Database

Issue the following SQL script to create a table and a sequence.

CREATE TABLE CUSTOMER(
	ID NUMBER(10) NOT NULL,
	NAME VARCHAR2(100) NOT NULL,
	EMAIL VARCHAR2(100) NOT NULL,
	CREATED_DATE DATE NOT NULL,
	CONSTRAINT CUSTOMER_PK PRIMARY KEY (ID)
);
CREATE SEQUENCE customer_seq
  MINVALUE 1
  MAXVALUE 9999999999
  START WITH 4
  INCREMENT BY 1;

2. JPA

In Java, add JPA annotations like this :

package com.mkyong.model;
import javax.persistence.*;
import java.util.Date;
@Entity
public class Customer {
    @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "CUST_SEQ")
    @SequenceGenerator(sequenceName = "customer_seq", allocationSize = 1, name = "CUST_SEQ")
    Long id;
    String name;
    String email;
    @Column(name = "CREATED_DATE")
    Date date;
    //...

References

1. Oracle / PLSQL: Sequences (Autonumber)
2. Spring Boot + Spring Data JPA + Oracle example