How to Map an Auto Increment Field in Hibernate

Java Hibernate id auto increment

Change the generator class to "identity" if you want an auto-generated value from the database.

Hibernate Auto Increment ID

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

and you leave it null (0) when persisting. (null if you use the Integer / Long wrappers)

In some cases the AUTO strategy is resolved to SEQUENCE rathen than to IDENTITY or TABLE, so you might want to manually set it to IDENTITY or TABLE (depending on the underlying database).

It seems SEQUENCE + specifying the sequence name worked for you.

Hibernate auto increment field for multiple databases

I would try and keep it as simple as possible and just mark the property with the insert=false, update=false attributes. I've ran into trouble before using the @Generated annotation with named queries, but insert/update=false has always worked as advertised.

Assign key value for auto increment field in hibernate

Hibernate while creating the auto increment id's create a pointer to the auto_increment value and gets the next id that can be used to save a new object and with this id the object is saved.

for example
When you save first object it gets auto_increment value as 1, it then uses 1 to save the object.
when you save second object it will get the auto_increment value as 2, it then uses this id to save the object.

learn more about id generation strategies

hibernate.hbm2ddl.auto just updates the database if there are any schema based changes

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