每2秒获取一次数据MySql

Question

我想每2秒获取一次数据并获得平均数据（如果它们有相同的时间）。

例如：

Number      value        Time
[ 1]        [20.1000]    '2014-04-07 17:11:04'    
[ 2]        [20.2000]    '2014-04-07 17:11:05'    
[ 3]        [20.3000]    '2014-04-07 17:11:05'    
[ 4]        [20.4000]    '2014-04-07 17:11:06'    
[ 5]        [20.5000]    '2014-04-07 17:11:06'  

结果应该是这样的。 ：

Number      Value        Time
[ 1]        [20.1000]    '2014-04-07 17:11:04'   
[ 4]        [20.4500]    '2014-04-07 17:11:06'   

我只是尝试每2秒钟获取一次数据而不使用..

进行平均

SELECT number,value,time FROM testdata WHERE time BETWEEN 17:00:00 AND 18.00:00
GROUP BY second(time) DIV 2

但是，它并没有给我带来好成绩。

谢谢。

Answer 1

没有测试，这样的事情应该这样做： -

SELECT `Time`, MIN(Number), AVG(value)
FROM testdata 
WHERE TIME(`Time`) BETWEEN '17:00:00' AND '18.00:00'
AND MOD(UNIX_TIMESTAMP(`Time`), 2) = 0
GROUP BY `Time`