我有3個表格,我正在加入他們以獲取一些數據。GROUP_CONCAT選項中的條件
----------------- Table Name: users ------------------------------- |user_id | user_name | ------------------------------- 123 | abc ------------------------------- 223 | bcd ------------------------------- 323 | cde ------------------------------- ----------------- Table Name: limit ------------------------------- user_id | limit_id ------------------------------- 123 | 1 ------------------------------- 223 | 2 ------------------------------- 323 | 3 ------------------------------- 323 | 4 ------------------------------- ------------------------- Table Name: limit_setting ------------------------------- limit_id | date_limit ------------------------------- 1 | 2016-09-29 12:00:00 ------------------------------- 2 | 2016-09-28 12:00:00 ------------------------------- 3 | 2016-09-27 12:00:00 ------------------------------- 1 | 2016-09-27 12:00:00 ------------------------------- 1 | 2016-09-24 12:00:00 ------------------------------- 4 | 2016-09-25 12:00:00 ------------------------------- 4 | 2016-09-26 12:00:00 -------------------------------
我需要得到這樣的結果。我被日期欄的GROUP_CONCAT卡住了。 日期列應包含除MAX日期以外的所有條目。如果在limit_id的limit_setting
表中只有一個條目,那麼它不應該爲該用戶顯示任何內容。 count_dates
:它在limit_setting
表中存在的條目數。
Desired output ---------------------------------------------------------------------- user_name | dates | count_dates ---------------------------------------------------------------------- abc | 2016-09-27 12:00:00 , 2016-09-24 12:00:00 | 3 ---------------------------------------------------------------------- bcd | | 1 ---------------------------------------------------------------------- cde | | 1 ----------------------------------------------------------------------- cde | 2016-09-26 12:00:00 | 2 -----------------------------------------------------------------------
SELECT PP.`user_name`, count(ESL.Limit_id) as count_dates,
GROUP_CONCAT(ESL.date_limit SEPARATOR ',') as dates
FROM users as PP INNER JOIN `limit` as PAL ON PP.Id = PAL.PlayerId
LEFT JOIN limit_setting as ESL ON ESL.LimitId = PAL.limitId
GROUP BY PAL.limitId
此外,我試着用(這什麼也沒有返回)
SELECT ESL.date_limit, MAX(date_limit) as max_date, PP.`user_name`, count(ESL.Limit_id) as count_dates,
GROUP_CONCAT(ESL.date_limit SEPARATOR ',') as dates
FROM users as PP INNER JOIN `limit` as PAL ON PP.Id = PAL.PlayerId
LEFT JOIN limit_setting as ESL ON ESL.LimitId = PAL.limitId
GROUP BY PAL.limitId
HAVING ESL.date_limit > max_date
我試着用Find_in_set
但不知道如何有效地使用它。
謝謝你這麼多的幫助和解釋......我從來沒有使用'SUBSTRING_INDEX'之前,並不知道它...再次感謝:) – user2595861