如何计算MySQL的时差？

Question

I have a table with column 'start', which contain the start date of some tasks

+----------+---------------------+------------+
| name     | start               | end        |
+----------+---------------------+------------+
| p1       | 2014-12-08 15:56:03 |            | 
| p2       | 2014-12-08 15:56:03 |            | 
| p3       | 2014-12-08 15:56:03 |            | 
| ...      | ...                 | ...        | 
+----------+---------------------+------------+

I need to select, from this table all the tasks started for more than 48h I tried

start between DATE_SUB(NOW(),INTERVAL 2 DAY) and  NOW()

I googled and tried several ways to compare date but unfortunately didn't get the result as expected.

Answer 1

I'm not fluent on the ways of doing this purely with mysql, but you could do the dates with PHP (since you tagged this as using PHP too):

$startDate = date("Y-m-d H:i:s",strtotime("-48 hours"));
$nowDate = date("Y-m-d H:i:s");
$sql = "select * from table where start >= '".$startDate."' AND start <= '".$nowDate."'";
// execute your sql statement here and fetch results