每当我尝试运行以下代码时,总是会收到此错误:
ObjectStateManager 中已存在具有相同键的对象。ObjectStateManager 无法跟踪具有相同键的多个对象。
这是我的代码
// find assessmentcase that needs to be updated
var CaseToBeUpdated = db.AssessmentCases
.Where(c => c.CaseSeq == score.CaseSeq)
.FirstOrDefault();
// create new assessmentcase with updated data
AssessmentCase assessmentcase = new AssessmentCase
{
CaseSeq = CaseToBeUpdated.CaseSeq,
DateClosed = System.DateTime.Now,
SeqClosedBy = SeqClosedBy,
UserIdClosed = User.Identity.Name,
};
// save changes to assessment case table
db.Entry(assessmentcase).State = EntityState.Modified;
db.SaveChanges();
本质上,我正在尝试更新assessmentcase
表中的一些数据。我究竟做错了什么?