سلام ساختار دیتابیسم به صورت زیر هست

من یک حلقه for دارم که یک سری اطلاعات میبره ذخیره میکنه

موقع اجرا کردن برنامه خطای زیر میده

کد :

            for (int i = 0; i <=10; i++)
            {
                voucherTree tree=new voucherTree();
                tree.voucherTreeID = 2;
                tree.Description = "DescriptionDescriptionDescriptionDescriptionDescriptionDescriptionDescription";
                tree.creditor = "125000";
                db.voucherTrees.Add(tree);
                db.SaveChanges();
            }

خطا :

Saving or accepting changes failed because more than one entity of type 'FTS_EF.Models.voucherTree' have the same primary key value. Ensure that explicitly set primary key values are unique. Ensure that database-generated primary keys are configured correctly in the database and in the Entity Framework model. Use the Entity Designer for Database First/Model First configuration. Use the 'HasDatabaseGeneratedOption" fluent API or 'DatabaseGeneratedAttribute' for Code First configuration.