留言本（2）数据操作基础类

 此留言本数据库用的是access，数据库名为book，有两个表为guestbook：留言记录表，admin：管理员用户名及密码表。

下面是数据基础类

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 System.Data.OleDb;

/// <summary>
/// DB 的摘要说明
/// </summary>
public class DB
{
    public DB()
    {
        //
        // TODO: 在此处添加构造函数逻辑
        //
    }
    public static OleDbConnection Getcon()   //用静态方法是为了方便，直接调用即可
    {
        OleDbConnection con = new OleDbConnection(ConfigurationManager.ConnectionStrings["BookConnectionString"].ConnectionString);   //数据库连接
        return con;
    }
    public static DataSet GetDataSet(string sql, string tablename)//得到一个数据集，为了以后数据绑定控件的数据源
    {
        OleDbConnection con = Getcon();
        con.Open();
        OleDbCommand cmd = new OleDbCommand(sql, con);
        OleDbDataAdapter adpt = new OleDbDataAdapter(cmd);
        DataSet ds = new DataSet();
        adpt.Fill(ds, tablename);
        return ds;
        con.Close();
        con.Dispose();

    }
    public static int ExecuteScalar(string query)//返回记录的第一行第一列
    {
        Int32 result;
        OleDbConnection con = Getcon();
        con.Open();
        OleDbCommand cmd = new OleDbCommand(query, con);
        result = (Int32)cmd.ExecuteScalar();
        con.Close();
        con.Dispose();

        return result;

    }
    public static void ExecuteNonQuery(string query)  //数据执行，更新数据库
    {
        OleDbConnection con = Getcon();
        con.Open();
        OleDbCommand cmd = new OleDbCommand(query, con);
        cmd.ExecuteNonQuery();

    }
    public static string ExecuteSca(string query)
    {
        string result;
        OleDbConnection con = Getcon();
        con.Open();
        OleDbCommand cmd = new OleDbCommand(query, con);
        result=(string )cmd.ExecuteScalar();
         return result;
      
       
 
    }

}