//增加庫存量
public void IncStock(XINEntities _context, string ProductID, int Quantity)
{
if (ProductID == null)
{
Exception ex = new Exception("計算庫存量的資料不可以含有空值！");
ex.Source = "null";
throw ex;
}
//定義影響的資料列數
int rowsAffected;
//更新庫存量
rowsAffected = _context.ExecuteStoreCommand(
"UPDATE Product SET Stock = Stock + {0} " +
"WHERE ProductID = {1} ",
Quantity, ProductID);
//檢查影響的資料列數
if (rowsAffected == 0)
{
//修改失敗，舉發例外
Exception ex = new Exception("計算庫存量發生不可預期的錯誤！");
ex.Source = "Quantity";
throw ex;
}
}
//減少庫存量
public void DecStock(XINEntities _context, string ProductID, int Quantity)
{
if (ProductID == null)
{
Exception ex = new Exception("計算庫存量的資料不可以含有空值！");
ex.Source = "null";
throw ex;
}
//重讀ObjectContext的庫存記錄
_context.Refresh(RefreshMode.StoreWins, _context.Product);
//查詢指定品項的庫存量
var qryStock = (from P in _context.Product
where P.ProductID == ProductID
select P.Stock).FirstOrDefault();
int CurrQty = (int)qryStock;
if ((CurrQty - Quantity) < 0)
{
Exception ex = new Exception(string.Format(
"商品編號{0}的庫存量不足，無法出貨！", ProductID));
ex.Source = "Stock";
throw ex;
}
//定義影響的資料列數
int rowsAffected;
//更新庫存量
rowsAffected = _context.ExecuteStoreCommand(
"UPDATE Product SET Stock = Stock - {0} " +
"WHERE ProductID = {1} ",
Quantity, ProductID);
//檢查影響的資料列數
if (rowsAffected == 0)
{
//修改失敗，舉發例外
Exception ex = new Exception("計算庫存量發生不可預期的錯誤！");
ex.Source = "Quantity";
throw ex;
}
}