ASP.NET 2.0實現數據訪問層

1. 實現數據訪問層

本節將講解數據訪問層的實現，該層包括與AdventureWorks數據庫通信的所有必要類和方法。首先，使用Visual Studio 2005創建新的Visual C#類庫項目AdventureWorksTraderDataAccess。當這個項目創建後，可修改默認類名稱為ProductCategoryDB。示例1說明了ProductCategoryDB類的實現代碼。

示例1：實現ProductCategoryDB類

using System;
using System.Data;
using System.Data.Common;
using System.Data.SqlClient;
using System.Collections.Generic;
using System.Text;
using AdventureWorksTraderEntities;
using Microsoft.Practices.EnterpriseLibrary.Data;
namespace AdventureWorksTraderDataAccess
{
public class ProductCategoryDB
{
private DataColumnMapping[] mappings = new DataColumnMapping[] { new DataColumnMapping("ProductCategoryID", "ProductCategoryID"), new DataColumnMapping("Name", "Name"), new DataColumnMapping("rowguid", "Rowguid"), new DataColumnMapping("ModifiedDate", "ModifiedDate") };
public IList〈ProductCategory> GetProductCategories()
{
IList〈ProductCategory> list = new List〈ProductCategory>();
Database db = DatabaseFactory.CreateDatabase();
string storedProcedureName = "GetProductCategories";
DbCommand dbCommand = db.GetStoredProcCommand(storedProcedureName);
using (IDataReader reader = db.ExecuteReader(dbCommand))
{
while (reader.Read())
{
ProductCategory temp = new ProductCategory();
ProductCategory category = (ProductCategory)DataAccessHelper.PopulateEntity(temp, mappings, reader);
list.Add(category);
}
}
return list;
}
}
}