public async Task <ActionResult <productHistory> > PostproductHistory(productHistory productHistory)
        {
            _context.productHistory.Add(productHistory);
            await _context.SaveChangesAsync();

            return(CreatedAtAction("GetproductHistory", new { id = productHistory.id }, productHistory));
        }
        public async Task <IActionResult> PutproductHistory(long id, productHistory productHistory)
        {
            if (id != productHistory.id)
            {
                return(BadRequest());
            }

            _context.Entry(productHistory).State = EntityState.Modified;

            try
            {
                await _context.SaveChangesAsync();
            }
            catch (DbUpdateConcurrencyException)
            {
                if (!productHistoryExists(id))
                {
                    return(NotFound());
                }
                else
                {
                    throw;
                }
            }

            return(NoContent());
        }