我如何平均MySQL结果集

Question

我有这个MySQL查询告诉我状态更改条目之间的区别：

SELECT 
    t1.`TRACKID` AS TicketNumber,
    TIMEDIFF(t2.`date`, t1.`date`) AS Difference
FROM
    hesk_history t1
    JOIN hesk_history t2 ON t2.`TRACKID` = t1.`TRACKID` AND t1.`Action` = 'Created' AND (t2.`Action` = 2)

给我以下结果集：

TicketNumber    Difference
2013-08-12-36   410:21:25
2013-06-12-91   00:01:22
2013-08-12-50   00:00:26

我如何AVG这个结果集？

Answer 1

http://www.w3schools.com/sql/sql_func_avg.asp 所以在你的情况下

选择     AVG（t1。TRACKID AS TicketNumber，     TIMEDIFF（t2。date，t1。date））AS差异 从     hesk_history t1     加入hesk_history t2 ON t2。TRACKID = t1。TRACKID AND t1。Action ='已创建'AND（t2。Action = 2）