MySQL的与WHERE

Question

我有以下查询多计数i制成：

SELECT COUNT(*) AS item_count, 
reseller_id, count(**WHERE sold=1**) as sold_count 
count(**WHERE refunded=1**) as rrefunded 
FROM store GROUP BY 
reseller_id 

出售是1或0和相同退款。

我想检查每个经销商销售多少和退款多少，但我不知道如何在一个查询中执行此操作。

Answer 1

如果1或0，你可以做SUM（）

SELECT SUM(sold) as sold_count, SUM(refunded) as refund_count FROM store 

Answer 2

试试这个：

SELECT 
    reseller_id, 
    COUNT(*) AS item_count, 
    sum(case sold when 1 then 1 else 0 end) as sold_count, 
    sum(case refunded when 1 then 1 else 0 end) as refunded_count 
FROM store 
GROUP by reseller_id