LINQ - From parent list get total count of values from nested list

Question

I am having a view model

 public class HouseReportMainModel
    {
        public int HouseId { get; set; }
        public int DisplayOrder { get; set; }
        public string HouseName { get; set; }
        public string HouseColor{ get; set; }
        public int TotalStudentCount { get; set; }
        public List<HouseReportViewModel> StudentList { get; set; }
    }

I will get the student list using linq and i need to fetch the count of the inner list and need to display that in parent view model

 var houseReportDetails = _dbContext.Set<HouseStudentMapping>()
                .AsNoTracking()
                .Include(i=>i.StudentClassMap.Student)
                .Include(i=>i.StudentClassMap.Class.Standard)
                .Include(i=>i.House)
                .Where(s => selectedClassIds.Contains(s.StudentClassMap.ClassId ?? 0) &&
                            selectedHouseIds.Contains(s.HouseId))
                .GroupBy(s => s.HouseId)
                .Select(s => new HouseReportMainModel()
                {
                    HouseId = s.Key,
                    DisplayOrder = s.Select(c=>c.House.DisplayOrder).FirstOrDefault(),
                    HouseName = s.Select(c => c.House.Name).FirstOrDefault(),
                    HouseColor = s.Select(c => c.House.Color).FirstOrDefault(),
                    StudentList = s.Select(t => new HouseReportViewModel()
                    {
                        StudentClassMapId = t.StudentClassMapId,
                        RollNumber = t.StudentClassMap.RollNumber??0,
                        StudentName = t.StudentClassMap.Student.Name,
                        ClassName = t.StudentClassMap.Class.Standard.Name+" "+ t.StudentClassMap.Class.Name,
                        HouseId = t.HouseId,
                        HouseName = t.House.Name,
                        ClassId = t.StudentClassMap.ClassId??0,
                        StandardId = t.StudentClassMap.Class.StandardId
                    }).ToList()
                }).ToList();

I need TotalStudentCount = StudentList.Sum(x => x.Distinct().Count() But how will i get the TotalStudentCount inside the linq list Could someone please help me.

@Roshmi your expected output is an object and not map. So instead of `.push`, try `obj[ keyName ] = value` — Rajesh, Apr 02 '20 at 06:23
https://stackoverflow.com/questions/26264956/convert-object-array-to-hash-map-indexed-by-an-attribute-value-of-the-object this helped me to find the result thank you @Rajesh — Roshmi Augustine, Apr 02 '20 at 06:49

Janak Shrestha · Accepted Answer · 2020-04-03T00:18:55.933

-1

try this

let value = [
    {text: 'Field0',value:'val' },
    {text: 'Field1',value:'val1' },
    {text: 'Field2',value:'val2' },
    {text: 'Field3',value:'val3' },
    {text: 'Field4',value:'val4' }
]
let newvalue = {}
value.map(item => newvalue [item.text] = item.value)
console.log(newvalue )

edited Apr 03 '20 at 00:18

answered Apr 02 '20 at 06:23

Janak Shrestha

26
2

1

This is not what OP is asking for. Take a closer look at the desired output – Sebastian Kaczmarek Apr 02 '20 at 06:23
1

This has the same output OP's code has – Rajesh Apr 02 '20 at 06:24
you want array of value? – Janak Shrestha Apr 02 '20 at 06:28
i need it the result like res ={field0,:val0, field1:val1, field2:val2 } – Roshmi Augustine Apr 02 '20 at 06:41
i have updated the code – Janak Shrestha Apr 03 '20 at 00:19

LINQ - From parent list get total count of values from nested list

1 Answers1