hibernate的异常:could not instantiate id generator

could not instantiate id generator
 
  dialect does not support sequesces
  我的hbm是
  <id name="id" type="string" column="id" >
  <generator class="uuid.hex"/>
  </id>
 
  数据库是sqlserver，对应的id属性是char 64   


------解决方法--------------------------------------------------------
class这个属性是产生主键的类
 
  如是char 64,你要写一个生成主键的类才可以