Mysql GROUP_CONCAT 基于计数相乘

Question

我正在尝试进行 mysql 查询，其中 GROUP_CONCAT 是 table 'shop_previews' 中的所有字符串。但是，当运行以下查询时，它会根据 "timesBought".

的数量重复它

select 
    `shop_items`.*, 
     group_concat(shop_previews.image) as images, 
     count(`shop_histories`.`shopId`) as `timesBought` 
from `shop_items`
left join `shop_previews` on `shop_previews`.`shopId` = `shop_items`.`id`
left join `shop_histories` on `shop_items`.`id` = `shop_histories`.`shopId`
group by `shop_items`.`id` 
order by `timesBought` desc

因此，如果 timesBought 等于二，并且 shop_previews.image 只有一个结果，它会将那个条目与自身连接起来，结果类似于

https://example.com/example.png,https://example.com/example.png

Answer 1

GROUP_CONCAT()支持DISTINCT:

GROUP_CONCAT(DISTINCT shop_previews.image) as images

Mysql GROUP_CONCAT 基于计数相乘

Mysql GROUP_CONCAT multiplies based on count

mysql

sql

group-by

group-concat