三层架构之数据库访问层(doc 6页)

三层架构之数据库访问层内容提要：
using System;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;
namespace DbBase
{
public abstract class Base
{
#region "Fields of base calss"
protected static string strConn = ConfigurationSettings.AppSettings["strConnection"];
protected static string strSQL;
#endregion
#region "Properties of base class"
  }
#endregion

#region "Functions of base class"
public Base()
{
//
// TODO: Add constructor logic here
//
}
/// <summary>
/// executing SQL commands
/// </summary>
/// <param name="strSQL">string</param>
/// <returns>return int</returns>
protected static int ExecuteSql(string strSQL)

..............................