How to annotate MYSQL autoincrement field with JPA annotations

Question

To use a MySQL AUTO_INCREMENT column, you are supposed to use an IDENTITY strategy:

@Id @GeneratedValue(strategy=GenerationType.IDENTITY)
private Long id;

Which is what you'd get when using AUTO with MySQL:

@Id @GeneratedValue(strategy=GenerationType.AUTO)
private Long id;

Which is actually equivalent to

@Id @GeneratedValue
private Long id;

In other words, your mapping should work. But Hibernate should omit the id column in the SQL insert statement, and it is not. There must be a kind of mismatch somewhere.

Did you specify a MySQL dialect in your Hibernate configuration (probably MySQL5InnoDBDialect or MySQL5Dialect depending on the engine you're using)?

Also, who created the table? Can you show the corresponding DDL?

Follow-up: I can't reproduce your problem. Using the code of your entity and your DDL, Hibernate generates the following (expected) SQL with MySQL:

insert 
into
    Operator
    (active, password, username) 
values
    (?, ?, ?)

Note that the id column is absent from the above statement, as expected.

To sum up, your code, the table definition and the dialect are correct and coherent, it should work. If it doesn't for you, maybe something is out of sync (do a clean build, double check the build directory, etc) or something else is just wrong (check the logs for anything suspicious).

Regarding the dialect, the only difference between MySQL5Dialect or MySQL5InnoDBDialect is that the later adds ENGINE=InnoDB to the table objects when generating the DDL. Using one or the other doesn't change the generated SQL.

Using MySQL, only this approach was working for me:

@Id @GeneratedValue(strategy=GenerationType.IDENTITY)
private Long id;

The other 2 approaches stated by Pascal in his answer were not working for me.

For anyone reading this who is using EclipseLink for JPA 2.0, here are the two annotations I had to use to get JPA to persist data, where "MySequenceGenerator" is whatever name you want to give the generator, "myschema" is the name of the schema in your database that contains the sequence object, and "mysequence" is the name of the sequence object in the database.

@GeneratedValue(strategy= GenerationType.SEQUENCE, generator="MySequenceGenerator")
@SequenceGenerator(allocationSize=1, schema="myschema",  name="MySequenceGenerator", sequenceName = "mysequence")

For those using EclipseLink (and possibly other JPA providers), it is CRITICAL that you set the allocationSize attribute to match the INCREMENT value defined for your sequence in the database. If you don't, you'll get a generic persistence failure, and waste a good deal of time trying to track it down, like I did. Here is the reference page that helped me overcome this challenge:

http://wiki.eclipse.org/EclipseLink/Examples/JPA/PrimaryKey#Using_Sequence_Objects

Also, to give context, here is what we're using:

Java 7 Glassfish 3.1 PostgreSQL 9.1 PrimeFaces 3.2/JSF 2.1

Also, for laziness' sake, I built this in Netbeans with the wizards for generating Entities from DB, Controllers from Entities, and JSF from Entities, and the wizards (obviously) do not know how to deal with sequence-based ID columns, so you'll have to manually add these annotations.

If you are using Mysql with Hibernate v3 it's ok to use GenerationType.AUTO because internally it will use GenerationType.IDENTITY, which is the most optimal in for MySQL.

However in Hibernate v5, It has changed. GenerationType.AUTO will use GenerationType.TABLE which generates to much queries for the insertion.

You can avoid that using GenerationType.IDENTITY (if MySQL is the only database you are using) or with these notations (if you have multiple databases):

@GeneratedValue(strategy = GenerationType.AUTO, generator = "native")
@GenericGenerator(name = "native", strategy = "native")

Please make sure that id datatype is Long instead of String, if that will be string then @GeneratedValue annotation will not work and the sql generating for

@Id @GeneratedValue(strategy=GenerationType.IDENTITY)
private String id;

create table VMS_AUDIT_RECORDS (id **varchar(255)** not null auto_increment primary key (id))

that needs to be

create table VMS_AUDIT_RECORDS (id **bigint** not null auto_increment primary key (id))

If you are using MariaDB this will work

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "id", updatable = false, nullable = false)
private Long id;

For more, you can check https://thorben-janssen.com/hibernate-tips-use-auto-incremented-column-primary-key/

I tried every thing, but still I was unable to do that, I am using mysql, jpa with hibernate, I resolved my issue by assigning value of id 0 in constructor Following is my id declaration code

@Id
@Column(name="id",updatable=false,nullable=false)
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;