为何此处的foreach语句不执行

Question

this.windConnection = new SqlConnection("Server=localhost; User=sa; PWD=111111;database=DFZQ;Asynchronous Processing=true");
            this.windConnection.Open();
            this.windCommand = this.windConnection.CreateCommand();windCommand.CommandText = "SELECT  stockCode,sum(volume) FROM [DFZQ].[dbo].[fundPortfolio] where stopDate='" + tradingDate + "'group by stockCode";
            SqlDataReader sdr5 = windCommand.ExecuteReader();
            Dictionary<string, double> getSumStockVolume1 = new Dictionary<string, double>();
            foreach (KeyValuePair<string, double> pair in getSumStockVolume1)
            {
                string stockCode = (string)sdr5["stockCode"];
                double sumStockVolume1 = (double)sdr5["sum(volume)"];
                getSumStockVolume1.Add(stockCode, sumStockVolume1);
            }
            sdr5.Close();
            return getSumStockVolume1;

Answer 1

ctionary<string, double> getSumStockVolume1 = new Dictionary<string, double>();
foreach (KeyValuePair<string, double> pair in getSumStockVolume1)
{}
getSumStockVolume1中没有数据...

Answer 2

getSumStockVolume1 没有数据怎么会执行。你要先有返回的数据集才行

Answer 3

ctionary<string, double> getSumStockVolume1 = new Dictionary<string, double>();
foreach (KeyValuePair<string, double> pair in getSumStockVolume1)
{}
getSumStockVolume1是你new出来的，没有数据，为空。

Answer 4

windCommand.CommandText = "SELECT stockCode,sum(volume) FROM [DFZQ].[dbo].[fundPortfolio] where stopDate='" + tradingDate + "'group by stockCode";
  SqlDataReader sdr5 = windCommand.ExecuteReader();
  Dictionary<string, double> getSumStockVolume1 = new Dictionary<string, double>();
  foreach (sdr5.Read())
  {
  string stockCode = (string)sdr5["stockCode"];
  double sumStockVolume1 = (double)sdr5["sum(volume)"];
  getSumStockVolume1.Add(stockCode, sumStockVolume1);
  }

Answer 5

失误！！！windCommand.CommandText = "SELECT stockCode,sum(volume) FROM [DFZQ].[dbo].[fundPortfolio] where stopDate='" + tradingDate + "'group by stockCode";
  SqlDataReader sdr5 = windCommand.ExecuteReader();
  Dictionary<string, double> getSumStockVolume1 = new Dictionary<string, double>();
  While(sdr5.Read())
  {
  string stockCode = (string)sdr5["stockCode"];
  double sumStockVolume1 = (double)sdr5["sum(volume)"];
  getSumStockVolume1.Add(stockCode, sumStockVolume1);
  } 这样就把它们放到字典dictionary里去了

Answer 6

漏了吧while(sdr5.Read())
{
  String stockCode = String.Empty;
  if(!sdr5.IsDBNull(0))
  {
    stockCode = sdr5.GetString(0);
  }  Int32 sum = -1;
  if(!sdr5.IsDBNull(1))
  {
    stockCode = sdr5.GetInt(1);
  }  if(!String.IsNullOrEmpty(stockCode)
    && sum >0 )
  {
    getSumStockVolume1.Add(stockCode, sum);
  }
}