/// <summary>
 /// 文件名稱:sqldataupdater.cs
 /// 摘    要:sql數(shù)據(jù)更新器,可方便對(duì)單數(shù)據(jù)表進(jìn)行讀,寫,刪操作,構(gòu)造函數(shù)按引用傳出結(jié)果集.
 ///    sqldataupdater du = new sqldataupdater(sqlhere,ref yourdataset)
 ///    調(diào)用update(ds)更新數(shù)據(jù),自動(dòng)事務(wù)處理,出錯(cuò)信息存在 errormessage.
 ///   
 /// 完成日期:2005-4-21
 /// 作    者:魏孫鼎
 /// 當(dāng)前版本:1.0 
 /// </summary>
 public class sqldataupdater
 {
  private sqlconnection  cn;
  private sqlcommand   cmd;
  private sqldataadapter  da;
  private sqltransaction  tran;
  private sqlcommandbuilder cmdbuilder;  
  private string    err;

  public string errormessage
  {
   get
   {
    return err;
   }
  }
  
  /// <summary>
  /// 初始化數(shù)據(jù)更新器
  /// </summary>
  /// <param name="sql">用于返回schema的sql</param>
  /// <param name="dataset">按引用傳遞的數(shù)據(jù)集</param>
  public sqldataupdater(string sql,ref dataset dataset)
  {
   err = "";
   if (dataset == null) dataset = new dataset();
   cn  = new sqlconnection(zmarketdata.datasetting.connectionstring);
   cmd = new sqlcommand(sql,cn);
   da  = new sqldataadapter(cmd);
   cmdbuilder = new sqlcommandbuilder(da);

   da.fill(dataset);   
  }

  public bool update(dataset ds)
  {
   bool success = false;
   cn.open();
   tran = cn.begintransaction();
   cmd.transaction = tran;
   try
   { 
    if(ds.getchanges() != null)
    {
     da.update(ds.getchanges());
    }
    success = true;
    tran.commit();
   }
   catch(exception ex)
   {
    tran.rollback();
    err = ex.message;
    success = false;
   }
   return success;   
  }

  ~sqldataupdater()
  {
   da.dispose();
   cmd.dispose();
   cn.dispose();
  }
 }

// 應(yīng)用示例

dataset ds = new dataset();      
sqldataupdater du = new sqldataupdater("select * from public_feedback where 1=2",ref ds);

datarow dr = ds.tables[0].newrow();

dr["createdate"] = datetime.now;
dr["firstname"]  = request["txtname"];
dr["companyname"] = request["txtcompany"];
dr["email"]   = request["txtemail"];

ds.tables[0].rows.add(dr);
 if (du.update(ds)) 
{
     //成功
}
else
{
     response.write(du.errormessage);
}