hibernate设置了not-null 为何无效

因为设错地方了！

错误--写在了property标签里

<property name="password" type="string" length="40" not-null="true">      <column name="password" ></column></property>

正确--写在column标签里

<property name="password" type="string" >      <column name="password" length="40" not-null="true"></column></property>