在ASP.NET 2.0中操作数据之六十五：在TableAdapters中创建新的存

　　完成向导后，TableAdapter将包含一个新的可用方法——GetProductByProductID(productID)，当调用该方法时，将执行我们刚刚创建的Products_SelectByProductID存储过程.花点时间在服务器资源管理器里查看该存储过程，点Stored Procedures文件夹，并打开Products_SelectByProductID(如果你没看到它，在Stored Procedures文件夹上右击鼠标，选“刷新”).

　　请注意，SelectByProductID存储过程将@ProductID作为输入参数，并执行我们在向导里输入的SELECT Statement，如下：

ALTER PROCEDURE dbo.Products_SelectByProductID
(
 @ProductID int
)
AS
 SET NOCOUNT ON;

SELECT ProductID, ProductName, SupplierID, CategoryID,
 QuantityPerUnit, UnitPrice, UnitsInStock, UnitsOnOrder,
 ReorderLevel, Discontinued
FROM Products
WHERE ProductID = @ProductID

第六步：创建一个业务逻辑层类

在我们打算从表现层访问产品前，我们首先需要为新添加的数据集创建一个BLL class，在~/App_Code/BLL文件夹里创建一个ProductsBLLWithSprocs.cs文件，如下：

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using NorthwindWithSprocsTableAdapters;

[System.ComponentModel.DataObject]
public class ProductsBLLWithSprocs
{
 private ProductsTableAdapter _productsAdapter = null;
 protected ProductsTableAdapter Adapter
 {
 get
 {
  if (_productsAdapter == null)
  _productsAdapter = new ProductsTableAdapter();

  return _productsAdapter;
 }
 }

 [System.ComponentModel.DataObjectMethodAttribute
 (System.ComponentModel.DataObjectMethodType.Select, true)]
 public NorthwindWithSprocs.ProductsDataTable GetProducts()
 {
 return Adapter.GetProducts();
 }


 [System.ComponentModel.DataObjectMethodAttribute
 (System.ComponentModel.DataObjectMethodType.Select, false)]
 public NorthwindWithSprocs.ProductsDataTable GetProductByProductID(int productID)
 {
 return Adapter.GetProductByProductID(productID);
 }


 [System.ComponentModel.DataObjectMethodAttribute
 (System.ComponentModel.DataObjectMethodType.Insert, true)]
 public bool AddProduct
 (string productName, int? supplierID, int? categoryID,
  string quantityPerUnit, decimal? unitPrice, short? unitsInStock,
  short? unitsOnOrder, short? reorderLevel, bool discontinued)
 {
 // Create a new ProductRow instance
 NorthwindWithSprocs.ProductsDataTable products =
  new NorthwindWithSprocs.ProductsDataTable();
 NorthwindWithSprocs.ProductsRow product = products.NewProductsRow();

 product.ProductName = productName;
 if (supplierID == null)
  product.SetSupplierIDNull();
 else
  product.SupplierID = supplierID.Value;
 if (categoryID == null)
  product.SetCategoryIDNull();
 else
  product.CategoryID = categoryID.Value;
 if (quantityPerUnit == null)
  product.SetQuantityPerUnitNull();
 else
  product.QuantityPerUnit = quantityPerUnit;
 if (unitPrice == null)
  product.SetUnitPriceNull();
 else
  product.UnitPrice = unitPrice.Value;
 if (unitsInStock == null)
  product.SetUnitsInStockNull();
 else
  product.UnitsInStock = unitsInStock.Value;
 if (unitsOnOrder == null)
  product.SetUnitsOnOrderNull();
 else
  product.UnitsOnOrder = unitsOnOrder.Value;
 if (reorderLevel == null)
  product.SetReorderLevelNull();
 else
  product.ReorderLevel = reorderLevel.Value;
 product.Discontinued = discontinued;

 // Add the new product
 products.AddProductsRow(product);
 int rowsAffected = Adapter.Update(products);

 // Return true if precisely one row was inserted, otherwise false
 return rowsAffected == 1;
 }

 [System.ComponentModel.DataObjectMethodAttribute
 (System.ComponentModel.DataObjectMethodType.Update, true)]
 public bool UpdateProduct
 (string productName, int? supplierID, int? categoryID, string quantityPerUnit,
 decimal? unitPrice, short? unitsInStock, short? unitsOnOrder,
 short? reorderLevel, bool discontinued, int productID)
 {
 NorthwindWithSprocs.ProductsDataTable products =
  Adapter.GetProductByProductID(productID);
 if (products.Count == 0)
  // no matching record found, return false
  return false;

 NorthwindWithSprocs.ProductsRow product = products[0];

 product.ProductName = productName;
 if (supplierID == null)
  product.SetSupplierIDNull();
 else
  product.SupplierID = supplierID.Value;
 if (categoryID == null)
  product.SetCategoryIDNull();
 else
  product.CategoryID = categoryID.Value;
 if (quantityPerUnit == null)
  product.SetQuantityPerUnitNull();
 else
  product.QuantityPerUnit = quantityPerUnit;
 if (unitPrice == null)
  product.SetUnitPriceNull();
 else
  product.UnitPrice = unitPrice.Value;
 if (unitsInStock == null)
  product.SetUnitsInStockNull();
 else
  product.UnitsInStock = unitsInStock.Value;
 if (unitsOnOrder == null)
  product.SetUnitsOnOrderNull();
 else
  product.UnitsOnOrder = unitsOnOrder.Value;
 if (reorderLevel == null)
  product.SetReorderLevelNull();
 else
  product.ReorderLevel = reorderLevel.Value;
 product.Discontinued = discontinued;

 // Update the product record
 int rowsAffected = Adapter.Update(product);

 // Return true if precisely one row was updated, otherwise false
 return rowsAffected == 1;
 }

 [System.ComponentModel.DataObjectMethodAttribute
 (System.ComponentModel.DataObjectMethodType.Delete, true)]
 public bool DeleteProduct(int productID)
 {
 int rowsAffected = Adapter.Delete(productID);

 // Return true if precisely one row was deleted, otherwise false
 return rowsAffected == 1;
 }
}

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