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[英]Fetching multiple records while sampling epoch timestamp feild from MySQL table?
[英]Fetching records by sampling epoch from MySQL table - selecting nearest value?
我有一張桌子,有像
TimeStamp | Feild1 | Feild 2
--------------------------------------
1902909002 | xyddtz | 233447
1902901003 | xytzff | 233442
1902901105 | xytzdd | 233443
1902909007 | xytzdd | 233443
1902909909 | xytsqz | 233436
現在我想查詢它並獲取諸如timestamp = 1902909002大約OR 1902901003大約OR的記錄...我希望我記錄每個最近的那個時代的時間
我寫了一些東西:
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";
這將返回null,並且如果date和date到目前為止具有較大的差異,則OR的單位為千。 任何機構都可以提出更好的方法嗎?
可以套用范圍嗎? 我的意思是這樣的:
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);
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