Question

我有一张基本表：

id  client  trans_date  returned
1    bob    20180301       0
2    frank  20180301       0
3    bob    20180401       1

id喜欢获得客户分组的结果，并计算购买的商品数量和退货数量。喜欢这个

name  bought returned
bob    1       1
frank  1       0

我尝试了这个，但它没有工作

SELECT 
     soldto AS name,
     IF(return=0,count(id),'0') AS bought,
     IF(return=1,count(id),'0') AS returned 
FROM sales 
WHERE sdate BETWEEN '20180201000000' AND '20180501000000'
group by soldto;

Answer 1

使用条件聚合

SELECT 
     soldto AS name,
     COUNT(*) AS bought,
     -- or maybe COUNT( CASE WHEN return = 0 THEN 1 END) AS bought,
     COUNT( CASE WHEN return = 1 THEN 1 END) AS returned 
FROM sales 
WHERE sdate BETWEEN '20180201000000' AND '20180501000000'
GROUP BY soldto;

group by搞砸我的计数mysql

1 个答案: