将MYSQL日期时间舍入至最短15分钟间隔（毫秒）（PHP） [英] Rounding a MYSQL datetime to earliest 15 minute interval in milliseconds (PHP)

问题描述

我从MYSQL中获取一个datetime，如下所示：

2010-08-11 11:18:28

我需要将其转换为最低或最早的15分钟间隔，并以毫秒为单位输出另一个功能。

所以，这种情况是：

2010-08-11 11:15:00（毫秒）

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$ b $哎哟！对不起 - 需要澄清 - 我需要代码，将其转换成毫秒ININ php！

---

测试显示以下内容：

  $ time_start = microtime（true）; （$ i = 0; $ i< 10000; $ i ++）
 floor（strtotime（'2010-08-11 23:59:59'）/（60 * 15））* 60 * 15 * 1000; 
 $ time_end = microtime（true）; 
 echo'time taken ='。（$ time_end  -  $ time_start）; 
  

时间= 21.440743207932

  $ time_start = microtime（true）; （$ i = 0; $ i< 10000; $ i ++）
 strtotime（'2010-08-11 23:59:59'） - （strtotime（'2010-08-11 23： 59:59'）％900）; 
 $ time_end = microtime（true）; 
 echo'time taken ='。（$ time_end  -  $ time_start）; 
  

时间= 39.597450017929

  $ time_start = microtime（true）; （$ i = 0; $ i< 10000; $ i ++）
 bcmul（（strtotime（'2010-08-11 23:59:59'） - （strtotime（'2010-08- 11 23:59:59'）％900）），1000）; 
 $ time_end = microtime（true）; 
 echo'time taken ='。（$ time_end  -  $ time_start）; 
  

时间= 42.297260046005

  $ time_start = microtime（true）; （$ i = 0; $ i< 10000; $ i ++）
 floor（strtotime（'2010-08-11 23:59:59'）/（900））* 900000; 
 $ time_end = microtime（true）; 
 echo'time taken ='。（$ time_end  -  $ time_start）; 
  

时间= 20.687357902527

时间= 19.32729101181

时间= 19.938629150391

看起来strtotime（）函数是一个缓慢的，我们可能应该避免使用它每次它需要的双倍。记录（60 * 15）！= timetaken（900）有点惊喜...

解决方案

工作？没有一些功能会更好吗？

  echo floor（strtotime（'2010-08-11 11:18 ：28'）/（60 * 15））* 60 * 15 * 1000; 
 1281505500000 
 2010年8月11日，星期三11:15:00 AM 
 
回显地板（strtotime（'2010-08-11 11:28:28'）/（60 * 15））* 60 * 15 * 1000; 
 1281505500000 
 2010年8月11日（星期三）11:15:00 AM 
 
回显层（strtotime（'2010-08-11 00:00:00'）/（60 * 15））* 60 * 15 * 1000; 
 1281465000000 
 2010年8月11日（星期三）12:00:00 AM 
 
 echo floor（strtotime（'2010-08-11 23:59:59'）/（60 * 15））* 60 * 15 * 1000; 
 1281550500000 
 2010年8月11日，星期三11:45:00 PM 
  

I'm fetching a datetime from MYSQL which looks like:

2010-08-11 11:18:28

I need to convert it into the "floor" or the earliest 15 minute interval and output in milliseconds for another function.

So, this case would be:

2010-08-11 11:15:00 in milliseconds

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Whoops! Sorry - need to clarify - I need code that will transform it into milliseconds WITHIN php!

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Doing a timing test revealed the following:

$time_start = microtime(true);
for($i=0;$i<10000;$i++)
    floor(strtotime('2010-08-11 23:59:59')/(60*15))*60*15*1000;
$time_end = microtime(true);
echo 'time taken = '.($time_end - $time_start);

time taken = 21.440743207932

$time_start = microtime(true);
for($i=0;$i<10000;$i++)
    strtotime('2010-08-11 23:59:59')-(strtotime('2010-08-11 23:59:59') % 900);
$time_end = microtime(true);
echo 'time taken = '.($time_end - $time_start);

time taken = 39.597450017929

$time_start = microtime(true);
for($i=0;$i<10000;$i++)
    bcmul((strtotime('2010-08-11 23:59:59')-(strtotime('2010-08-11 23:59:59') % 900)), 1000);
$time_end = microtime(true);
echo 'time taken = '.($time_end - $time_start);

time taken = 42.297260046005

$time_start = microtime(true);
for($i=0;$i<10000;$i++)
    floor(strtotime('2010-08-11 23:59:59')/(900))*900000;
$time_end = microtime(true);
echo 'time taken = '.($time_end - $time_start);

time taken = 20.687357902527

time taken = 19.32729101181

time taken = 19.938629150391

It appears that the strtotime() function is a slow one and we probably should avoid using it doubly for every time its required. The timetaken(60*15) != timetaken(900) was a little bit of a surprise...

解决方案

Would this work? Isn't there some function that would do this better?

echo floor(strtotime('2010-08-11 11:18:28')/(60*15))*60*15*1000;
1281505500000
Wednesday, August 11, 2010 11:15:00 AM

echo floor(strtotime('2010-08-11 11:28:28')/(60*15))*60*15*1000;
1281505500000
Wednesday, August 11, 2010 11:15:00 AM

echo floor(strtotime('2010-08-11 00:00:00')/(60*15))*60*15*1000;
1281465000000
Wednesday, August 11, 2010 12:00:00 AM

echo floor(strtotime('2010-08-11 23:59:59')/(60*15))*60*15*1000;
1281550500000
Wednesday, August 11, 2010 11:45:00 PM

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