幫助MySQL查詢 - 省略，分組？

Question

做一些調查和寫一個日誌數據庫的查詢。

我已經加入了很多表來恢復我需要的數據，但我想清理一下。

該查詢返回所有用戶以及他們的帳戶上啓用了哪些功能。

這裏是我想要做的清理：

他們的是一種叫做有兩種狀態的行動「，「添加」和「刪除」

如果用戶特徵列有'刪除'的行動，那麼我想不顯示任何行的同一功能，該用戶也被標記爲'添加'

這可能嗎？！

這是我到目前爲止有：

select users.id as site_id, users.company_name, feature_log.featurecode, feature.minimum_account as feature_type, users.account_type as site_type, account_types.name as account, feature_log.action, feature_log.time 
from users 
inner join 
    feature_log 
    on users.id = feature_log.siteid 
inner join 
    feature 
    on feature_log.featurecode = feature.featurecode 
inner join account_types 
    on users.account_type_INC = account_types.id 
where feature.minimum_account != 0 
    AND feature.minimum_account > users.account_type 
    AND users.status = 'Y' 
    ORDER BY feature_log.time DESC 

感謝您的支持！

Answer 1

所以，以「靜音」的所有功能，已經在時間上給定用戶「刪除」在任何時候，你可以添加一個（左）參加在以下子查詢：

SELECT DISTINCT users.id as siteid, feature_log.featurecode, TRUE as mute_feature 
FROM users 
INNER JOIN feature_log ON (users.id = feature_log.siteid) 
WHERE action = 'removed' 

這將是特定用戶在某個時間點停用的功能列表。然後在您的查詢的WHERE條款，你會添加像這樣的過濾器：

AND NOT IFNULL(mute_feature, FALSE) 

從本質上講，這會帶給你整個查詢是：

select users.id as site_id, users.company_name, feature_log.featurecode, feature.minimum_account as feature_type, users.account_type as site_type, account_types.name as account, feature_log.action, feature_log.time 
from users 
inner join 
    feature_log 
    on users.id = feature_log.siteid 
left join (
    SELECT DISTINCT users.id as siteid, feature_log.featurecode, TRUE as mute_feature 
    FROM users 
    INNER JOIN feature_log ON (users.id = feature_log.siteid) 
    WHERE action = 'removed' 
) as muted_features ON (feature_log.siteid = muted_features.siteid AND feature_log.featurecode = muted_features.featurecode) 
inner join 
    feature 
    on feature_log.featurecode = feature.featurecode 
inner join account_types 
    on users.account_type_INC = account_types.id 
where feature.minimum_account != 0 
    AND feature.minimum_account > users.account_type 
    AND users.status = 'Y' 
    AND NOT IFNULL(mute_feature, FALSE) 
    ORDER BY feature_log.time DESC