`지원되지 않음…`예외를 던지는 중첩 된 LINQ 방법

Question

이것은 여기에서 후속 조치입니다 ->다중 소개-온 -LINQ-NESTED- 메드 .

기본적으로 let memberName = ... 이 예외를 던지고 있습니다 Method 'System.String MemberName(Int32)' has no supported translation to SQL. 그리고 나는 해결책을 알아 내지 않습니다.

또한, BLLCmo 그리고 BLLConnect 실제로 사용합니다 둘 다른 데이터베이스. 원래 앱 (광산이 아님)은 4 개의 분리 된 DB를 사용하므로 기한을 만들려고합니다.

---

BLLCmo.cs

    public static DataTable GetAllMembers(Guid workerID)
    {
        var AllEnrollees = from enrollment in context.tblCMOEnrollments
                               where enrollment.CMOSocialWorkerID == workerID || enrollment.CMONurseID == workerID
                               join supportWorker in context.tblSupportWorkers on enrollment.EconomicSupportWorkerID equals supportWorker.SupportWorkerID into workerGroup
                               from worker in workerGroup.DefaultIfEmpty()
                               let memberName = BLLConnect.MemberName(enrollment.ClientID)
                               orderby enrollment.DisenrollmentDate ascending, memberName ascending 
                               select new
                                       {
                                           enrollment.ClientID,
                                           MemberName = memberName,
                                           NurseName = BLLAspnetdb.NurseName(enrollment.CMONurseID),
                                           SocialWorkerName =BLLAspnetdb.SocialWorkerName(enrollment.CMOSocialWorkerID),
                                           enrollment.DisenrollmentDate,
                                           enrollment.EnrollmentDate,
                                           ESFirstName = worker.FirstName,
                                           ESLastName = worker.LastName,
                                           ESPhone = worker.Phone
                                       };

        var dataTable = AllEnrollees.CopyLinqToDataTable();

        return dataTable;
    }

---

BLLConnect.cs

    public static String MemberName(Int32 personID)
    {
        var memberName = from person in context.tblPersons
                         where person.PersonID == personID
                         select person.FirstName + " " + person.LastName;

        return memberName.SingleOrDefault();
    }

Answer 1

문제는 LINQ에서 SQL이 메소드를 SQL로 변환하려고한다는 것입니다. 부터 MemberName 유효한 SQL이 아니며 포기합니다. 대신, SQL에서 필요한 데이터를 끌어 내고 별도의 LINQ에서 메소드 (및 정렬)를 호출하여 개체 쿼리를 호출해야합니다.

public static DataTable GetAllMembers(Guid workerID)
{
    var AllEnrollees =
        from enrollment in context.tblCMOEnrollments
        where enrollment.CMOSocialWorkerID == workerID || enrollment.CMONurseID == workerID
        join supportWorker in context.tblSupportWorkers on enrollment.EconomicSupportWorkerID equals supportWorker.SupportWorkerID into workerGroup
        from worker in workerGroup.DefaultIfEmpty()
        select new
        {
            enrollment.ClientID,
            enrollment.CMONurseID,
            enrollment.CMOSocialWorkerID,
            enrollment.DisenrollmentDate,
            enrollment.EnrollmentDate,
            ESFirstName = worker.FirstName,
            ESLastName = worker.LastName,
            ESPhone = worker.Phone
        };

    var result =
        from enrollee in AllEnrollees.AsEnumerable()
        let memberName = BLLConnect.MemberName(enrollee.ClientID)
        orderby enrollee.DisenrollmentDate ascending, memberName ascending 
        select new
        {
            enrollee.ClientID,
            MemberName = memberName,
            NurseName = BLLAspnetdb.NurseName(enrollee.CMONurseID),
            SocialWorkerName = BLLAspnetdb.SocialWorkerName(enrollee.CMOSocialWorkerID),
            enrollee.DisenrollmentDate,
            enrollee.EnrollmentDate,
            enrollee.ESFirstName,
            enrollee.ESLastName,
            enrollee.ESPhone
        };

    return result.CopyLinqToDataTable();
}