The specified type member ‘DeleteFlag‘ is not supported in LINQ to Entities. Only initializers, entity members, and entity navigation properties are supported.

出現這個問題的原因是因為在linq中兩個連接表創建的實體類需要吧其中的映射字段每一個都查出來，不然就會報這個錯誤，錯誤的寫法如下

                var querySql = from t in _observationResultRepository.Table
                               join r 
 
in _observationRequestRepository.Table
                               on t.ObservationUID equals r.ObservationUID
                               select new RelatedLabResultInfo 
                               {
                                   ValueText=t.ValueText,
                                   ResultDate
 
=r.ResultDate
                               };
  if (query.ClinicInfoType != null)
                {
                    querySql = querySql.Where(u => u.ClinicInfoType == query.ClinicInfoType.Value.ToString());
                }

這其中，tostringEF 不支持，需要寫個中間變量賦值然後再放在EF中，

正確的寫法：

                var
 
 querySql = from t in _observationResultRepository.Table
                               join r in _observationRequestRepository.Table
                               on t.ObservationUID equals r.ObservationUID
                               select new RelatedLabResultInfo 
                               {
                                   ValueText=t.ValueText,
                                   ResultDate=r.ResultDate,
                                   ClinicInfoType=r.ClinicInfoType
                               };

  if (query.ClinicInfoType != null) 
                {
                    ClinicInfoType = query.ClinicInfoType.Value.ToString();
                }

if (query.ClinicInfoType != null)
                {
                    querySql = querySql.Where(u => u.ClinicInfoType == ClinicInfoType);
                }

指定類型的成員XX”不支持實體LINQ。只有初始化，成員單位，和實體導航性能的支持。