sum()函数计算时间

[wudaobugu]

mysql 用sum(liezhi) -->leizhi是time类型。当好像计算出的结果不正确，不知道是怎么回事？

[WWWWA]

计算分钟、小时？将记录及正确结果贴出来看看

[wudaobugu]

select sum(total_time) from balance_conf_account where start_time>'2007-01-01 00:00:00' and end_time<'2009-01-01 00:00:00
' and end_time!='0000-00-00 00:00:00' and card_index=1;
+-----------------+
| sum(total_time) |
+-----------------+
| 8446 |
+-----------------+
1 row in set
mysql>
select SECOND
(total_time) from balance_conf_account where start_time>'2007-01-01 00:00:00' and end_time<'2009-01-01 00:00:00' and end_time!='0000-00-00 00:00:00' and card_index=1;
+--------------------+
| SECOND(total_time) |
+--------------------+
| 0 |
| 50 |
| 12 |
| 42 |
| 42 |
+--------------------+
5 rows in set
mysql>
select MINUTE
(total_time) from balance_conf_account where start_time>'2007-01-01 00:00:00' and end_time<'2009-01-01 00:00:00' and end_time!='0000-00-00 00:00:00' and card_index=1;
+--------------------+
| MINUTE(total_time) |
+--------------------+
| 43 |
| 20 |
| 10 |
| 10 |
| 0 |
+--------------------+

select HOUR
(total_time) from balance_conf_account where start_time>'2007-01-01 00:00:00' and end_time<'2009-01-01 00:00:00' and end_time!='0000-00-00 00:00:00' and card_index=1;
+------------------+
| HOUR(total_time) |
+------------------+
| 0 |
| 0 |
| 0 |
| 0 |
| 0 |
+------------------+
用第一种是8000多秒

第二,第三，第四的总和才5000多点。、不知是怎么回事？

[WWWWA]

应该按小时、分、秒计算，结果准确一些，没有看到记录

[wudaobugu]

不知道结果为什么会有偏差？

[wudaobugu]

哦，我知道了。mysql漏洞：他那个分钟时乘以100的，不是60.

[WWWWA]

简单一点，用5条记录来测试，看看两种方法的结果是否一致

[WWWWA]

呵呵，学到了，没有想到是这个原因

[wudaobugu]

我那有个乱码的问题 一直没有解决，希望大哥帮助看看。