public void DeleteCouponUser(Coupon_User coupon_user)
{
if (coupon_user == null)
{
throw new ArgumentNullException(nameof(coupon_user));
}
context.Coupon_Users.Remove(coupon_user);
}
public void AddCouponUser(Coupon_User coupon_user)
{
if (coupon_user == null)
{
throw new ArgumentNullException(nameof(coupon_user));
}
context.Coupon_Users.Add(coupon_user);
}
public async Task <Coupon_User> AddCouponToUserAsync(int couponID, Guid userID)
{
var optionsBuilder = new DbContextOptionsBuilder <MallDbContext>();
optionsBuilder.UseMySql(configuration.GetConnectionString("DefaultConnection"));
using (MallDbContext mContext = new MallDbContext(optionsBuilder.Options))
{
var coupon = await mContext.Coupons.FindAsync(couponID);
if (coupon == null)
{
return(null);
}
if (coupon.CouponCount <= 0)
{
return(null);
}
var couponUser = await mContext.Coupon_Users
.Include(c => c.Coupon)
.Where(c => c.CouponID == couponID &&
c.UserID.Equals(userID))
.FirstOrDefaultAsync();
if (couponUser == null)
{
coupon.CouponCount--;
couponUser = new Coupon_User
{
CouponID = couponID,
UserID = userID,
RecievedCount = 1,
RemainedCount = 1
};
mContext.Coupon_Users.Add(couponUser);
try
{
await mContext.SaveChangesAsync();
}
catch (DbUpdateConcurrencyException)
{
return(null);
}
}
else
{
if (couponUser.RecievedCount >= coupon.AllowLimit)
{
return(null);
}
coupon.CouponCount--;
couponUser.RecievedCount++;
couponUser.RemainedCount++;
try
{
await mContext.SaveChangesAsync();
}
catch (DbUpdateConcurrencyException)
{
return(null);
}
}
return(couponUser);
}
}
public void UpdateCouponUser(Coupon_User coupon_user)
{
//no need code
}