public async Task<bool> Update(DriverCategory item)
        {
            var cate = await IdExist(item.Id);
            cate.Name = item.Name;
            cate.Value = item.Value;

            _db.Entry(cate).State = EntityState.Modified;
            try
            {
                await _db.SaveChangesAsync();
            }
            catch (DbUpdateConcurrencyException exception)
            {
                throw new DbUpdateConcurrencyException(exception.Message);
            }

            return true;
        }
        public async Task<DriverCategory> Add(DriverCategory item)
        {
            var cate = new DriverCategory
            {
                Name = item.Name,
                Value = item.Value
            };

            cate = _db.DriverCategory.Add(cate);
            try
            {
                await _db.SaveChangesAsync();
                return cate;
            }
            catch (DbUpdateConcurrencyException exception)
            {
                throw new DbUpdateConcurrencyException(exception.Message);
            }
        }