c# - How to group by on 2 child entities and get total of both this child entities?

Question

I want to get total variants run for my Test Version 0 i.e Test Id=100

This is my table and records:

Test:

Id      Version
100        0

Variants:

Id      Name       Type   CategoryId
11      Variant1   Diff     2
12      Variant1   Add      2
13      Variant2   Add      3
14      Variant2   Diff     2
15      Variant3   Add      6

SubVariants:

Id     VariantId     Name
66      11           Abc
67      11           PQR
68      11           Xyz

69      12           Abc
70      12           PQR
71      12           Xyz

72      13           Abc
73      13           PQR

74      14           Abc
75      14           PQR
76      14           Xyz

77      15           ABC
78      15           PQR

TestOperation:

Id   TestId    SourceSubVariantId   TargetSubVariantId   variation
1     100       69                    70                   0
1     100       70                    71                   20
1     100       72                    73                   90

TestOperationDifference:

Id   TestId    SourceSubVariantId   TargetSubVariantId   Unmatch
1     100       66                    67                   0
1     100       67                    68                   2
1     100       74                    75                   7
1     100       75                    76                   0
1     100       77                    78                   26

So from the above records there are total 3 variants run on 2 types of operation i.e TestOperation and TestOperationDifference and below are the 3 variants for specific Test 100:

Variants1(This run in TestOperation)
Variants2(This run in TestOperation)
Variants3(This run in TestOperationDifference)

This above 3 parent variants will come as because all this parent child variants are being used in 2 tables i.e TestOperation and TestOperationDifference.

So for finding total parent variants I need to figure out from both the tables (TestOperation and TestOperationDifference) corresponding child variants are used and based on that I need to count total parent variants.

This is my class:

public class Test
        {
            public int Id { get; set; }
            public string Version { get; set; }
            public virtual ICollection<TestOperation> TestOperation { get; set; }
            public virtual ICollection<TestOperationDifference> TestOperationDifference { get; set; }
        }

        public class TestOperation
        {
            public int Id { get; set; }
            public Nullable<int> TestId { get; set; }
            public int SourceSubVariantId { get; set; }
            public int TargetSubVariantId { get; set; }
            public int  variation { get; set; }
            public virtual SubVariants SubVariants { get; set; }
            public virtual SubVariants SubVariants1 { get; set; }
            public virtual Test Test { get; set; }

        }

        public class TestOperationDifference
        {
            public int Id { get; set; }
            public Nullable<int> TestId { get; set; }
            public int SourceSubVariantId { get; set; }
            public int TargetSubVariantId { get; set; }

            public int unmatch { get; set; }

            public virtual SubVariants SubVariants { get; set; }
            public virtual SubVariants SubVariants1 { get; set; }
            public virtual Test Test { get; set; }
        }

        public class Variants
        {
            public int Id { get; set; }
            public string Name { get; set; }
            public string Type { get; set; }
            public int CategoryId { get; set; }

            public virtual ICollection<SubVariants> SubVariants { get; set; }

            public virtual Category Category { get; set; }
        }

        public class SubVariants
        {
            public int Id { get; set; }
            public int VariantId { get; set; }
            public string Name { get; set; }

            public virtual Variants Variants { get; set; }
            public virtual ICollection<TestOperationDifference> TestOperationDifference { get; set; }

            public virtual ICollection<TestOperationDifference> TestOperationDifference1 { get; set; }
            public virtual ICollection<TestOperation> TestOperation { get; set; }
            public virtual ICollection<TestOperation> TestOperation1 { get; set; }
        }

My query:

var data =(from mk in context.Test
                  select new 
                  {

                      TotalVariants = (mk.TestOperation.Select(t => t.SubVariants).Count()
                                   +
                                      mk.TestOperationDifference.Select(t => t.SubVariants).Count())
                    }).ToList();

Output :8

Expected output:3

Answer 1

From top of my head, assuming I understood your confusing description. I think you need to union variants from both TestOperation and TestOperationDifference, then distinct and count them. Not sure if this will work in EF.

let toQuery = context.Test.SelectMany(mk=>TestOperation.Select(t=>t.SubVariants.Variants));
let todQuery = context.Test.SelectMany(mk=>TestOperationDifference.Select(t=>t.SubVariants.Variants));

let total = toQuery.Concat(todQuery).Disctinct().Count;

Also, your naming is confusing. You are using plural (s) for single-item references and you have SourceControlDetailId in your model that is not in table and have SubVariants and SubVariants1 instead of SourceSubVariant and TargetSubVariant. I would recommend to fix this first.