migration-guide.adoc

6.2 Migration Guide

Table of Contents

• Default DDL type changes
  • UUID mapping changes on MariaDB
  • UUID mapping changes on SQL Server

This guide discusses migration from Hibernate ORM version 6.2. For migration from earlier versions, see any other pertinent migration guides as well.

• 6.1 Migration guide

• 6.0 Migration guide

Default DDL type changes

UUID mapping changes on MariaDB

On MariaDB, the type code SqlType.UUID now by default refers to the DDL type uuid, whereas before it was using binary(16). Due to this change, schema validation errors could occur on existing databases.

The migration to uuid requires a migration expression like cast(old as uuid).

To retain backwards compatibility, configure the setting hibernate.type.preferred_uuid_jdbc_type to BINARY.

UUID mapping changes on SQL Server

On SQL Server, the type code SqlType.UUID now by default refers to the DDL type uniqueidentifier, whereas before it was using binary(16). Due to this change, schema validation errors could occur on existing databases.

The migration to uuid requires a migration expression like cast(old as uuid).

To retain backwards compatibility, configure the setting hibernate.type.preferred_uuid_jdbc_type to BINARY.