Hibernate UUID with PostgreSQL and SQL Server

Question

I have an application I would like to run on both PostgreSQL and SQL Server. I would like to use java.util.UUID as the IDs.

I have defined my columns in SQL Server a

Answer 1

I ended up writing my own Dialect and BasicType that links the Java type java.util.UUID to uuid-char by default.

This class is inspired by the PostgreSQLDialect

public class MySQLServerDialect extends SQLServer2012Dialect {

    public void contributeTypes(TypeContributions typeContributions, ServiceRegistry serviceRegistry) {
        super.contributeTypes( typeContributions, serviceRegistry );

        typeContributions.contributeType( SQLServerUUIDType.INSTANCE );
    }
}

This class is inspired by the UUIDCharType

public class SQLServerUUIDType extends AbstractSingleColumnStandardBasicType implements LiteralType {
    public static final SQLServerUUIDType INSTANCE = new SQLServerUUIDType();

    public SQLServerUUIDType() {
        super( VarcharTypeDescriptor.INSTANCE, UUIDTypeDescriptor.INSTANCE );
    }

    @Override
    protected boolean registerUnderJavaType() {
        return true;
    }

    public String getName() {
        return "my-uuid";
    }

    public String objectToSQLString(UUID value, Dialect dialect) throws Exception {
        return StringType.INSTANCE.objectToSQLString( value.toString(), dialect );
    }
}

I don't think it's the most elegant solution, but it works for now.