MySQL數(shù)據(jù)庫(kù)多表之間的查詢
問(wèn)題描述
問(wèn)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(fù)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(gè)field，SQL的邏輯會(huì)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(fù)雜哦，同問(wèn)，這樣的sql怎么寫(xiě)，我在想是不是可以寫(xiě)個(gè)存儲(chǔ)過(guò)程，畢竟存儲(chǔ)過(guò)程處理這樣復(fù)雜的邏輯容易一點(diǎn)
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