MySQL查詢統計，統計唯一值並分組

做個筆記

SQLyog客戶端訪問MySQL服務器

統計數據：次數總數， 次數成功率，對象(obj)總數，對象(obj)成功率

要求：按時間排序和分組

 

sql語句如下：

SELECT 
a.date AS `日期`,
a.total AS `總次數`,
a.objs AS `總對象數`,
ROUND(a.failed / a.total * 100, 2) AS `失敗次數比率`,
ROUND(a.obj_failed/ a.objs * 100, 2) AS `對象失敗率`
FROM
(SELECT 
COUNT(1) AS `total`,
COUNT(DISTINCT(`obj_id`)) AS `objs`,
COUNT(IF(`description` LIKE '%object failed%', 1, NULL)) AS `failed`,
COUNT(DISTINCT(IF(`description` LIKE '%object failed%', `obj_id`, NULL))) AS `obj_failed`,
DATE(`created_at`) AS `date`
FROM `mydb.my_table` WHERE `created_at` > '2016-03-07 0'
GROUP BY `date`
ORDER BY `date` DESC)
AS a