feat: optimize join queries in InsuranceListRepository for improved data retrieval

CompanyManagment.EFCore/Repository/InsuranceListRepository.cs

@@ -1594,19 +1594,25 @@ public class InsuranceListRepository : RepositoryBase<long, InsuranceList>, IIns
             .Where(x => x.LeftWorkInsurances.Any(l=>l.StartWorkDate <= firstDayOfMonth && 
                 (l.LeftWorkDate == null || l.LeftWorkDate >= firstDayOfMonth)));
         
-        var res = await notCreatedWorkshop
-            .GroupJoin(_context.WorkshopEmployers,
+        var res =  await notCreatedWorkshop
+            .Join(
+                _context.WorkshopEmployers
+                    .OrderBy(we => we.WorkshopId)
+                    .ThenBy(we => we.EmployerId)
+                    .GroupBy(we => we.WorkshopId)
+                    .Select(g => g.First()),
                 workshop => workshop.id,
-                workshopEmployer => workshopEmployer.WorkshopId,
-                (workshop, workshopEmployer) => new { workshop, workshopEmployer })
-            .SelectMany(x => x.workshopEmployer.DefaultIfEmpty(), (x, workshopEmployer) => new { x.workshop, workshopEmployer })
-            .GroupJoin(_context.Employers,
-                allResult => allResult.workshopEmployer.EmployerId,
-                employer => employer.id,
-                (allResult, employer) => new { allResult.workshop, allResult.workshopEmployer, employer })
-            .SelectMany(x => x.employer.DefaultIfEmpty(), (x, employer) => new { x.workshop, x.workshopEmployer, employer })
-            .Select(x => new InsuranceListViewModel
-            {
+                employer => employer.WorkshopId,
+                (workshop, workshopEmployer) => new
+                {
+                    workshop,
+                    workshopEmployer,
+                    employer = _context.Employers
+                        .FirstOrDefault(e => e.id == workshopEmployer.EmployerId)
+                }
+            )
+            .Select(x=> new InsuranceListViewModel
+                {
                 WorkShopId = x.workshop.id,
                 WorkShopCode = x.workshop.InsuranceCode,
                 WorkShopName = x.workshop.InsuranceWorkshopInfo != null ? x.workshop.InsuranceWorkshopInfo.WorkshopName : x.workshop.WorkshopFullName,