public class dbmanage
 {
  public dbmanage()
  {
   //
   // TODO: 在此处添加构造函数逻辑
   //
  }
  public SqlConnection GetConnection()//建立数据库连接
  {
   SqlConnection cn=new SqlConnection();
   cn.ConnectionString=System.Configuration.ConfigurationSettings.AppSettings["conn"];
   cn.Open();
   return cn;
  }
  public void delid(int intId ,string strTable,SqlConnection cn)
  {
   SqlCommand DeleteCmd=new SqlCommand ("delete from "+strTable+" where id="+intId,cn);
   DeleteCmd.ExecuteNonQuery();
  }
  public void ExecuteSql(string strSql,SqlConnection cn) //执行无返回值的sql命令
  {
   SqlCommand ExecuteCmd=new SqlCommand (strSql,cn);
   ExecuteCmd.ExecuteNonQuery();
   ExecuteCmd.Dispose();
  }

  public void UpdateTb(string strTbName, string strFieldsName,string strValue,int intId, SqlConnection cn)
  {
   SqlCommand UpdateCmd=new SqlCommand ("update strTbName set "+strFieldsName+"="+strValue+" where Id="+intId.ToString(),cn);
   UpdateCmd.ExecuteNonQuery();
  }
  public DataSet FillDs(string strSql, SqlConnection cn)
  {
   SqlDataAdapter FillDsAdapter=new SqlDataAdapter(strSql,cn);
   FillDsAdapter.SelectCommand.CommandType=CommandType.Text ;
   DataSet ds =new DataSet();
   FillDsAdapter.Fill(ds);
   FillDsAdapter.Dispose();
   return ds;
  }
  public DataSet FillDs(string strSql, SqlConnection cn,string srcTable)
  {
   SqlDataAdapter FillDsAdapter=new SqlDataAdapter(strSql,cn);
   FillDsAdapter.SelectCommand.CommandType=CommandType.Text ;
   DataSet ds =new DataSet();
   FillDsAdapter.Fill(ds,srcTable);
   FillDsAdapter.Dispose();
   return ds;
  }
  public string GetString(string strSql,SqlConnection cn)//获取字符串
  {
   string strGetString="";
   SqlDataAdapter FillDsAdapter=new SqlDataAdapter(strSql,cn);
   FillDsAdapter.SelectCommand.CommandType=CommandType.Text ;
   DataSet ds =new DataSet();
   FillDsAdapter.Fill(ds);
   if(ds.Tables[0].Rows.Count==1)
   {
    strGetString=ds.Tables[0].Rows[0][0].ToString();
   }
   else
   {
    strGetString=null;
   }
   FillDsAdapter.Dispose();
   ds.Dispose();
   return strGetString;
  }

 }