C#•2y ago

Cannot add multiple same objects to DB, only distinct are saved. .NET EntityFramework

I have a template of exercise with name, description and amount of sets. I want to create multiple objects of Exercise * amount of sets. For example I have template [{ "name" : "Legs", "sets" : 3 }, { "name" : "Arms", "sets" : 2 } in DB I want to be saved [ {legs}, {legs}, {legs}, {arms}, {arms}], but only [{legs}, {arms}] are saved.

            var exercises = planTemplate.Exercises
                .SelectMany(x => Enumerable.Repeat(new Exercise
                {
                    Name = x.Name,
                    Description = x.Description
                }, x.Sets))
                .ToList() ?? new List<Exercise>();

            var plan = new FitnessPlan
            {
                TemplateId = planTemplate.Id,
                Archived = false,
                User = user,
                Name = planTemplate.Name,
                Exercises = exercises,
            };

            await _context.FitnessPlans.AddAsync(plan);
            await _context.SaveChangesAsync();

            var exercises = planTemplate.Exercises
                .SelectMany(x => Enumerable.Repeat(new Exercise
                {
                    Name = x.Name,
                    Description = x.Description
                }, x.Sets))
                .ToList() ?? new List<Exercise>();

            var plan = new FitnessPlan
            {
                TemplateId = planTemplate.Id,
                Archived = false,
                User = user,
                Name = planTemplate.Name,
                Exercises = exercises,
            };

            await _context.FitnessPlans.AddAsync(plan);
            await _context.SaveChangesAsync();

In attached screen they are all saved with exerciseId 1024 or 1025 instead of all be unique in range 1024-1028. In property exercises i have 5 objects without IDs but entityframework after saving changes gives them same IDs for objects with same structures, altho they are diffenent objeects.