如何在Linq中进行合并或分组？ 我得到的倍数值想用'，'合并数据

Question

my Query:

var s = entities.Doctors.SingleOrDefault(x => x.AreaId == id);
                    var z = (from x in entities.Doctors
                             join y in entities.Areas on x.AreaId equals y.AreaId
                             join s1 in entities.Availabilties on s.D_Id equals s1.DoctorId
                             join s2 in entities.Eductions on s.D_Id equals s2.DoctorId
                             join s3 in entities.DoctorSpecialities on s.D_Id equals s3.DoctorId 
                             join s4 in entities.Specialities on s3.SpecialityId equals s4.SpecialityId
                             join s5 in entities.DaysDetails on s1.DaysId equals s5.DaysId
                             join s6 in entities.Degrees on s2.DegreeId equals s6.DegreeId
                             where x.AreaId.Equals(id)
                             select new DoctorDisplay
                             {
                                 D_name = x.D_Name,
                                 D_address = x.D_Address,
                                 D_Area = y.AreaName,
                                 D_Contact1 = x.D_Contactone, 
                                 D_Contact2 = x.D_Contacttwo,
                                 D_fax = x.D_Faxno,
                                 D_SpecialityName = s4.SpecialityName,
                                 D_Availstarttime = s1.StartTime,
                                 D_Availlasttime = s1.LastTime,
                                 D_Availday= s5.DaysName,
                                 D_DegreeName = s6.DegreeName,
                                 D_Awards = x.D_Address,
                                 D_Status = x.D_Status
                              }).ToList();

****Getting Output****

[{"D_name":"Shanu","D_address":"block123","D_Area":"Manama","D_Contact1":"123","D_Contact2":"456","D_fax":"789","D_SpecialityName":"Dietician","D_Availstarttime":"9PM","D_Availlasttime":"11PM","D_Availday":"Sunday","D_DegreeName":"MBBS","D_Awards":"block123","D_Status":"Available"},{"D_name":"Shanu","D_address":"block123","D_Area":"Manama","D_Contact1":"123","D_Contact2":"456","D_fax":"789","D_SpecialityName":"Dietician","D_Availstarttime":"9PM","D_Availlasttime":"11PM","D_Availday":"Sunday","D_DegreeName":"Dentistdegree","D_Awards":"block123","D_Status":"Available"},{"D_name":"Shanu","D_address":"block123","D_Area":"Manama","D_Contact1":"123","D_Contact2":"456","D_fax":"789","D_SpecialityName":"Ayurveda","D_Availstarttime":"9PM","D_Availlasttime":"11PM","D_Availday":"Sunday","D_DegreeName":"MBBS","D_Awards":"block123","D_Status":"Available"},{"D_name":"Shanu","D_address":"block123","D_Area":"Manama","D_Contact1":"123","D_Contact2":"456","D_fax":"789","D_SpecialityName":"Ayurveda","D_Availstarttime":"9PM","D_Availlasttime":"11PM","D_Availday":"Sunday","D_DegreeName":"Dentistdegree","D_Awards":"block123","D_Status":"Available"},{"D_name":"Shanu","D_address":"block123","D_Area":"Manama","D_Contact1":"123","D_Contact2":"456","D_fax":"789","D_SpecialityName":"Dietician","D_Availstarttime":"4AM","D_Availlasttime":"11AM","D_Availday":"Monday","D_DegreeName":"MBBS","D_Awards":"block123","D_Status":"Available"},{"D_name":"Shanu","D_address":"block123","D_Area":"Manama","D_Contact1":"123","D_Contact2":"456","D_fax":"789","D_SpecialityName":"Dietician","D_Availstarttime":"4AM","D_Availlasttime":"11AM","D_Availday":"Monday","D_DegreeName":"Dentistdegree","D_Awards":"block123","D_Status":"Available"},{"D_name":"Shanu","D_address":"block123","D_Area":"Manama","D_Contact1":"123","D_Contact2":"456","D_fax":"789","D_SpecialityName":"Ayurveda","D_Availstarttime":"4AM","D_Availlasttime":"11AM","D_Availday":"Monday","D_DegreeName":"MBBS","D_Awards":"block123","D_Status":"Available"},{"D_name":"Shanu","D_address":"block123","D_Area":"Manama","D_Contact1":"123","D_Contact2":"456","D_fax":"789","D_SpecialityName":"Ayurveda","D_Availstarttime":"4AM","D_Availlasttime":"11AM","D_Availday":"Monday","D_DegreeName":"Dentistdegree","D_Awards":"block123","D_Status":"Available"}]

Group_concat on the basis of Education Id, DoctorspecialitiesID, Avaibilities Id, Image of Input and desire Output

Answer 1

Looking at you example output, it looks less like you want to "concat the data by ','" as much as you want to convert it to JSON.

Inwhichcase, you'd probably be better off using a tool like Newtonsoft's JSON.NET

UPDATE (based on comments): Assume doctors is the result of the query given in question.

var output = 
    from d in doctors
     group d by new { d.D_NAME, d.D_Area } into dg
     select new DoctorDisplay
     {
        D_NAME = dg.Key.D_NAME,
        D_Area = dg.Key.D_Area,
        D_SpecialityName = String.Join(",", dg.Select(d => d.D_SpecialityName).Distinct()),
        D_DegreeName = String.Join(",", dg.Select(d => d.D_DegreeName).Distinct())
    };