//Edit the amount of book
public void EditAmount(int bookId, int bookAmount)
{
int user_id = Convert.ToInt32(Session["user_id"]);
CART cart_temp = db.CART.Where(u => u.USER_ID == user_id).FirstOrDefault();
CART_INCLUDE book_temp = db.CART_INCLUDE.Where(u => u.USER_ID == user_id).Where(u => u.BOOK_ID == bookId).FirstOrDefault();
BOOK book = db.BOOK.Find(bookId);
decimal delta = (decimal)bookAmount - (decimal)book_temp.QUANTITY;
cart_temp.QUANTITY += delta;
cart_temp.TOTAL_PRICE += delta * book.PRICE;
book_temp.QUANTITY = bookAmount;
book_temp.TOTAL_PRICE = book.PRICE * bookAmount;
db.SaveChanges();
}
//Remove book
public void RemoveBook(int bookId)
{
int user_id = Convert.ToInt32(Session["user_id"]);
CART_INCLUDE book_temp = db.CART_INCLUDE.Where(u => u.USER_ID == user_id).Where(u => u.BOOK_ID == bookId).FirstOrDefault();
CART cart_temp = db.CART.Where(u => u.USER_ID == user_id).FirstOrDefault();
//Judge whether the cart is empty
if (cart_temp.QUANTITY != book_temp.QUANTITY)
{
cart_temp.QUANTITY -= book_temp.QUANTITY;
}
else
{
db.CART.Remove(cart_temp);
}
db.CART_INCLUDE.Remove(book_temp);
db.SaveChanges();
}
public ActionResult addCart(int ID)
{
int times = 1;
int price = db.Database.SqlQuery <int>("select PRICE from BOOK where ID=" + ID.ToString()).FirstOrDefault();
int user_id;
if (Session["user_id"] != null)
{
user_id = Convert.ToInt32(Session["user_id"]);
}
else
{
return(Redirect("~/Home/Login"));
}
int num = db.Database.SqlQuery <int>("select QUANTITY from CART_INCLUDE where BOOK_ID=" + ID.ToString() + " and USER_ID=" + user_id.ToString()).FirstOrDefault(); //当前购买该书数量
if (num == 0) //目前
{
CART_INCLUDE temp1 = new CART_INCLUDE();
temp1.USER_ID = user_id;
temp1.BOOK_ID = ID;
temp1.QUANTITY = times;
temp1.TOTAL_PRICE = price * times;
db.CART_INCLUDE.Add(temp1);
}
else
{
var temp = from u in db.CART_INCLUDE
where u.BOOK_ID == ID && u.USER_ID == user_id
select u;
temp.FirstOrDefault().QUANTITY += times;
temp.FirstOrDefault().TOTAL_PRICE += price * times;
}
int cart_num = db.Database.SqlQuery <int>("select count(*) from CART where USER_ID=" + user_id.ToString()).FirstOrDefault(); //当前用户购物车记录
if (cart_num == 0) //购物车为空
{
CART temp2 = new CART();
temp2.USER_ID = user_id;
temp2.QUANTITY = times;
temp2.TIME_START = DateTime.Now.ToString();
int cost = 15 - 3 * times;
if (cost < 0)
{
cost = 0;
} //计算邮费
temp2.POST_COST = cost;
temp2.TOTAL_PRICE = times * price;
db.CART.Add(temp2);
}
else//购物车不为空
{
var result = from u in db.CART
where u.USER_ID == user_id
select u;
result.FirstOrDefault().QUANTITY += times;
result.FirstOrDefault().TIME_START = DateTime.Now.ToString();
int cost = 15 - 3 * Convert.ToInt32(result.FirstOrDefault().QUANTITY);
if (cost < 0)
{
cost = 0;
}
result.FirstOrDefault().POST_COST = cost;
}
db.SaveChanges();
return(Redirect("Index?ID=" + ID.ToString()));
}
