asp.net - 通过从MySQL表中采样纪元来获取记录-选择最接近的值？

Question

我有一张 table ，里面有这样的字段

TimeStamp     |  Feild1      | Feild 2
--------------------------------------
1902909002    |  xyddtz      | 233447
1902901003    |  xytzff      | 233442
1902901105    |  xytzdd      | 233443
1902909007    |  xytzdd      | 233443
1902909909    |  xytsqz      | 233436

现在我想查询它并获取记录，例如时间戳= 1902909002大约或1902901003大约或...我希望记录最接近该纪元的每个纪元时间

我写了一些东西:

 string sqlQuery = "SELECT TimeStamp, FwdHr, W FROM Meter_Data WHERE (TimeStamp <= "+timeSt[0].ToString();
                    for (int i = 1; i < timeSt.Count; i++)
                    {
                        sqlQuery = sqlQuery + " OR TimeStamp <= " +timeSt[i].ToString() ;
                    }

                    sqlQuery=sqlQuery+ ") AND MeterID = @meterID AND DeviceID = @deviceID ORDER BY TimeStamp";

它返回 null，而且如果从日期到日期有很大的差异，OR 的值将是数千。有谁能提出更好的方法吗？

Answer 1

你能应用一个范围吗？我的意思是这样的:

var max=timeSt.Max();
var min=timeSt.Min();


var sqlString= string.Format(@"
SELECT 
    TimeStamp, 
    FwdHr, 
W 
    FROM 
    Meter_Data 
WHERE
    TimeStamp BETWEEN {0} AND {1}
    AND MeterID = @meterID AND DeviceID = @deviceID 
ORDER BY 
    TimeStamp",min,max);