Как я могу получить различие между двумя метками времени в течение многих дней? Я должен использовать столбец даты и времени для этого?
mysql> SELECT NOW(), last_confirmation_attempt, NOW() - last_confirmation_attempt AS diff FROM DateClubs HAVING diff IS NOT NULL ;
+---------------------+---------------------------+-----------------+
| NOW() | last_confirmation_attempt | diff |
+---------------------+---------------------------+-----------------+
| 2010-03-30 10:52:31 | 2010-03-16 10:41:47 | 14001084.000000 |
+---------------------+---------------------------+-----------------+
1 row in set (0.00 sec)
Я не думаю diff
находится в секундах, потому что, когда я делюсь diff
числом секунд за день (86,400), я не получаю ответ sensical:
mysql> SELECT NOW(), last_confirmation_attempt, ( NOW() - last_confirmation_attempt) / 86400 AS diff FROM DateClubs HAVING diff IS NOT NULL ;
+---------------------+---------------------------+----------------+
| NOW() | last_confirmation_attempt | diff |
+---------------------+---------------------------+----------------+
| 2010-03-30 10:58:58 | 2010-03-16 10:41:47 | 162.0568402778 |
+---------------------+---------------------------+----------------+
1 row in set (0.00 sec)
Если вы хотите игнорировать временную часть в столбцах, DATEDIFF() даст вам искомую разницу в днях.
SELECT DATEDIFF('2010-10-08 18:23:13', '2010-09-21 21:40:36') AS days;
+------+
| days |
+------+
| 17 |
+------+
CREATE TABLE t (d1 timestamp, d2 timestamp);
INSERT INTO t VALUES ('2010-03-11 12:00:00', '2010-03-30 05:00:00');
INSERT INTO t VALUES ('2010-03-11 12:00:00', '2010-03-30 13:00:00');
INSERT INTO t VALUES ('2010-03-11 00:00:00', '2010-03-30 13:00:00');
INSERT INTO t VALUES ('2010-03-10 12:00:00', '2010-03-30 13:00:00');
INSERT INTO t VALUES ('2010-03-10 12:00:00', '2010-04-01 13:00:00');
SELECT d2, d1, DATEDIFF(d2, d1) AS diff FROM t;
+---------------------+---------------------+------+
| d2 | d1 | diff |
+---------------------+---------------------+------+
| 2010-03-30 05:00:00 | 2010-03-11 12:00:00 | 19 |
| 2010-03-30 13:00:00 | 2010-03-11 12:00:00 | 19 |
| 2010-03-30 13:00:00 | 2010-03-11 00:00:00 | 19 |
| 2010-03-30 13:00:00 | 2010-03-10 12:00:00 | 20 |
| 2010-04-01 13:00:00 | 2010-03-10 12:00:00 | 22 |
+---------------------+---------------------+------+
5 rows in set (0.00 sec)