MySQL數據庫多表之間的查詢
問題描述
問題解答
回答1:思路一分兩種情況選出符合要求的company_id并union
把這些company_id的earning求和(2013-2014)
連接上company_name
好像搞的比較復雜。
with cid(id) as ( select company_id from tableB where year = 2014 and earning > 20 union select company_id from tableB where year in (2013, 2014) group by company_id having sum(earning) > 50), cid_earning(id, earning) as ( select company_id, sum(earning) from tableB where company_id in (select id from cid) and year in (2013, 2014) group by company_id)select a.company_name, c.earningfrom cid_earning c left join tableA a using(id)思路二
如果把2013和2014年的earning作為表的兩個field,SQL的邏輯會清晰很多:
withe3(id, earning) as ( select company_id, earning from tableB where year = 2013), e4(id, earning) as ( select company_id, earning from tableB where year = 2014)select a.company_name, e3.earning + e4.earning as earningfrom e3 inner join e4 using(id)left join tableA a using(id)where e4.earning > 20 or e3.earning + e4.earning > 50回答2:
好復雜哦,同問,這樣的sql怎么寫,我在想是不是可以寫個存儲過程,畢竟存儲過程處理這樣復雜的邏輯容易一點
相關文章:
1. 關docker hub上有些鏡像的tag被標記““This image has vulnerabilities””2. MySQL數據庫中文亂碼的原因3. macos - mac下docker如何設置代理4. docker不顯示端口映射呢?5. docker - 各位電腦上有多少個容器啊?容器一多,自己都搞混了,咋辦呢?6. angular.js - angularjs的自定義過濾器如何給文字加顏色?7. docker gitlab 如何git clone?8. android studio總是在processes running好久9. java - 請問在main方法中寫成對象名.屬性()并賦值,與直接參參數賦值輸錯誤是什么原因?10. css - C#與java開發Windows程序哪個好?
