Hibernate generates column of type “numeric” in SQL Server for properties of type Long of Java class. Is there a way to make Hibernate generate bigint (or int) column instead of numeric using the Hibernate hbm2ddl?
Taken from the hibernate forums: https://forum.hibernate.org/viewtopic.php?p=2377674#2377674
Looks like you're going to have to roll your own SQL server dialect. While that doesn't seem right, there doesn't seem to be any action in hibernate's JIRA that makes me think this is fixed.
Oh, or it could be driver type. I'm not sure what driver you're using but jTDS appears to map Long to BigInt.