简单的SQL Server数据库数据读取与数据操作-数据库

public DataSet Query(string SQLText)
  {
   SqlConnection myConnection=new SqlConnection(ConfigurationSettings.AppSettings["conn"]);
   DataSet ds = new DataSet();
   SqlDataAdapter myCommand = new SqlDataAdapter(SQLText,myConnection);
   myCommand.Fill(ds);
   return ds;
  }

//执行查询,返回SqlDataReader
  public  SqlDataReader QueryByReader(string sqlstr)
  {
   if (sqlstr==String.Empty)
    return null;
  
   SqlConnection myConnection = new SqlConnection(ConfigurationSettings.AppSettings["connstring"]);
   SqlCommand myCommand = new SqlCommand(sqlstr, myConnection);

   myConnection.Open();
   SqlDataReader result = myCommand.ExecuteReader(CommandBehavior.CloseConnection);
  
   return result;
  }

  //操作数据库,不返回结果
  public  bool OperateDB(string sqlstr)
  {
   if (sqlstr==String.Empty)
    return false;

   SqlConnection myConnection = new SqlConnection(ConfigurationSettings.AppSettings["connstring"]);
   SqlCommand myCommand = new SqlCommand(sqlstr, myConnection);

   myConnection.Open();
   myCommand.ExecuteNonQuery();
   myConnection.Close();

   return true;
  }