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:

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.

Answer 2

Update

Ok Learning, here it is a solution..

var tot_variants_for_test =
    (from v_name in 
       (from t_op in test 
        select new { v_name = t_op.TestOperation.Select(sv => sv.SubVariants.Variants.Name) }
       ).First().v_name 
     select v_name)
    .Union(
    (from v_name in 
      (from t_opdf in test 
       select new { v_name = t_opdf.TestOperationDifference.Select(sv => sv.SubVariants.Variants.Name) }
     ).First().v_name
     select v_name))
   .Count();

Answer 3

from test in Tests
where version == 0
let opsVariants = test.TestOperations
  .SelectMany(x => x.SourceSubVariant.Variant).Distinct()
let diffsVariants = test.TestOperationDifferences
  .SelectMany(x => x.SourceSubVariant.Variant).Distinct()
let variants = opsVariants.Union(diffsVariants)
select variants.Count();