BigInteger ID columns

pledge · **Joined:** Sun Jan 14, 2007 2:52 pm **Posts:** 19

I have an existing database and raw JDBC based project that I would like to transfer over to Hibernate with Annotations. I have so far written a very simple class to simluate the real project.

Code:

@Id @GeneratedValue
BigInteger id;
@Column(length = 100)
String forename;
@Column(length = 100)
String surname;
@Column(scale = 10, precision = 2)
BigDecimal money;
BigInteger bigNumber;

I am using MySQL dialect against MySQL 4.1. The ID column is "ID BIGINT UNSIGNED NOT NULL AUTO_INCREMENT".
The type of the current ID field on all tables is mapped to java.math.BigInteger.

When I try to persist an object I recieve the following error.

Quote:

this id generator generates long, integer, short or string; nested exception is org.hibernate.id.IdentifierGenerationException: this id generator generates long, integer, short or string
Caused by: org.hibernate.id.IdentifierGenerationException: this id generator generates long, integer, short or string

When I follow the advice given in the exception and use Long everything is happy and the object persists. However the MySQL documentation shows BigInteger as the recommended type to map to[1], so I would like to stick with it. Also I have a large number of references to these objects already and would prefer not to have to refactor so much code. Is there a way to continue to use BigInteger for my ID columns?

Thank you,
Martin.

[1]http://dev.mysql.com/doc/refman/5.0/en/connector-j-reference-type-conversions.html

tenwit · **Joined:** Thu Dec 23, 2004 9:08 pm **Posts:** 2008

Write a new generator class that extends org.hibernate.id.IdentityGenerator, and override getResult:

Code:

return rs.getBigDecimal(1).toBigInteger();

Then specify that class in your @Id annotation (I don't know how to do that bit).

pledge · **Joined:** Sun Jan 14, 2007 2:52 pm **Posts:** 19

Thank you. I will have a look around for some more examples now I have a starting point. What I currently have in the manual JDBC is (BigInteger)rs.getObject("ID"); so I should be able to continue using that in the generator class.