我有以下hibernate映射：

 <class name="Domain.Roomreservation, Core" table="Reservationroom">
    <id name="ID" unsaved-value="undefined">
        <generator class="native">
            <!--<param name="sequence">GLOBALSEQUENCE</param>-->
        </generator>
    </id>

    <property name="FromTime" not-null="true" index="IDX_RESRAUM_FromTime" />
    <property name="UntilTime" not-null="true" index="IDX_RESRAUM_UntilTime"/>

    <many-to-one name="Booking" column="Book_ID" index="IDX_RAUMRES_BOOK" lazy="false"
        class="Domain.Booking, Core" not-null="true" />
    </class>

而Reservationroom表如下所示：

ID         <pk>
Book_ID    <fk>
FromTime
UntilTime
....
....

我的hibernate查询看起来像：

String hql = "UPDATE Roomreservation as rr set rr.FromTime= 12:15" +
                     "Inner Join Booking b ON rr.Book_ID= b.ID " +
                     "Where b.ID = 95637";
                        IQuery query = CurrentSession.CreateQuery(hql);
                        int result = query.ExecuteUpdate();
                        Debug.WriteLine("Rows affected: " + result);

但是我总是 Error: NHibernate.Hql.Ast.ANTLR.QuerySyntaxException

有人可以帮我如何使它正常工作吗？