Mysql subquery group by error

Question

我想做一個子查詢來找出兩個信息。這裏是我得到

SELECT b.boroughName, SUM(c.crimeCount), 
    (SELECT SUM(c.crimeCount) 
    FROM FYP_Borough b JOIN FYP_Crime c on b.boroughID=c.boroughID 
    WHERE offenceID=8 
    GROUP BY boroughName) AS DrugUse 
FROM FYP_Borough b JOIN FYP_Crime c ON b.boroughID=c.boroughID 
GROUP BY b.boroughName 

此代碼是我得到的錯誤： 子查詢返回多個1行

我通過boroughName想組，否則它給我的每個字段的值相同。我該怎麼做呢？

Answer 1

SELECT b.boroughName, SUM(c.crimeCount), 
    SUM(CASE WHEN offenceID=8 THEN c.crimeCount ELSE 0 END) 
AS DrugUse 
FROM FYP_Borough b JOIN FYP_Crime c ON b.boroughID=c.boroughID 
GROUP BY b.boroughName