Linq 中join實現多條件左串連

例子如下：

public dynamic GetPersonByDirector(string directorCode,int assessCycle)        {            var query = from person in container.T_BASE_PERSON                        join plan in container.T_PLAN_PLAN on                            new {PERSON_ID = person.ID, ASSESS_CYCLE = (int?) assessCycle} equals                            new {plan.PERSON_ID, plan.ASSESS_CYCLE} into temp                        from personPlan in temp.DefaultIfEmpty()                        join assessinfo in container.T_BASE_ASSESSINFO on person.ID equals assessinfo.PERSON_ID                        join org in container.T_BASE_ORG on assessinfo.DEPT_ORG_CODE equals org.ORG_CODE                        where assessinfo.DIRECTORS_ID.Contains(directorCode) && assessinfo.ASSESS_CYCLE == assessCycle                        select new                                   {                                       PERSON_CODE = person.PERSON_CODE,                                       PERSON_NAME = person.PERSON_NAME,                                       ORG_NAME = org.ORG_NAME,                                       STATUS = personPlan == null ? -1 : personPlan.STATUS,                                       //左串連，可能為空白，下同                                       ID = person.ID,                                       PLAN_ID = personPlan == null ? 0 : personPlan.ID                                   };            return query.AsQueryable();        }

如代碼中紅色標紅所示。