wiwengweng wen [http://community.jboss.org/people/wiwengweng] created the discussion "the db schema creation explaination" To view the discussion, visit: http://community.jboss.org/message/632189#632189 -------------------------------------------------------------- this is how I debug the codes, and find out something I don't understand so far. I use mysql db, when codes go into "createGroup", one record is created in the jbpm_id_group table. can someone tell me how the commandService work? what is the "execute" function mean?? :) hope to learn and heard from you~ Vincent appended codes: identityService.createGroup("management"); public String createGroup(String groupName) {     return commandService.execute(new CreateGroupCmd(groupName, null, null));   } public interface CommandService {     String NAME_TX_REQUIRED_COMMAND_SERVICE = "txRequiredCommandService";   String NAME_NEW_TX_REQUIRED_COMMAND_SERVICE = "newTxRequiredCommandService";   /**    * @throws JbpmException if command throws an exception.    */   <T> T execute(Command<T> command); } public class CreateGroupCmd implements Command<String> {   private static final long serialVersionUID = 1L;   protected String groupName;   protected String groupType;   protected String parentGroupId;   public CreateGroupCmd(String groupName, String groupType, String parentGroupId) {     this.groupName = groupName;     this.groupType = groupType;     this.parentGroupId = parentGroupId;   }   public String execute(Environment environment) throws Exception {     IdentitySession identitySession = environment.get(IdentitySession.class);     return identitySession.createGroup(groupName, groupType, parentGroupId);   } } -------------------------------------------------------------- Reply to this message by going to Community [http://community.jboss.org/message/632189#632189] Start a new discussion in jBPM at Community [http://community.jboss.org/choose-container!input.jspa?contentType=1&...]