Transaction in SCA

[lili <ll...@163.com>]

Hello,
       I want to ask some questions about the transaction in SCA.
      First,how can the SCA ensure the transaction when I use SCA?
     I have thought ascene ,it is very easy,the detail is as follows:
         In the composite file,I have two components(we named them A and B),each component has a reference which is binded to an ejb, and I add a component then,this component's implementation is that it has two references which are the previous two components,and the component is promoted as a service in the scadomain.
 
           Now my question is ,if the two component'services also have add,delete,update  operations to the database, they have their own transaction control, the method of the service in the scadomain is update data of A and B, then how can I control the transaction of the method?It means that ,first the data of A is updated successfully, but the updating data of B is failed ,how can I use the transaction control in SCA to make the updating data of A is also rolling back? It is make the two operations be in one transction .
 
  Hope your reply!Thanks a lot!!!