我需要提取与特定值 ( CourseCode
) 对应的任意数量的记录,并将这些记录插入到另一个表中。只要Linq
代码只返回一条记录,此代码就可以正常工作,但是如果有更多记录,我会收到以下消息:
ObjectStateManager 中已存在具有相同键的对象。现有对象处于已修改状态。一个对象只有在被添加的情况下才能再次添加到 ObjectStateManager 中。
下面是我的代码:
if (_db == null) _db = new AgentResourcesEntities();
var prodCodes = from records in _db.CourseToProduct
where records.CourseCode == course.CourseCode
select records;
foreach (var pt in prodCodes.ToList())
{
agentProdTraining.SymNumber = symNumber;
agentProdTraining.CourseCode = course.CourseCode;
agentProdTraining.ProductCode = pt.ProductCode;
agentProdTraining.DateTaken = course.DateTaken;
agentProdTraining.Method = course.Method;
agentProdTraining.LastChangeOperator = requestor;
agentProdTraining.LastChangeDate = DateTime.Now;
agentProdTraining.DateExpired = course.ExpirationDate;
agentProdTraining.ProductCode = pt.ProductCode;
agentProdTraining.NoteId = pt.NoteId;
_db.AgentProductTraining.AddObject(agentProdTraining);
_db.SaveChanges();
PtAdded++;
EventLog.WriteEntry(sSource, "Product Training added", EventLogEntryType.Warning);
}