SQL:如何从group by语句中获取更多信息

尝试此操作-删除invoice.shoplocation

SELECT  
invoice.customer_name,  
invoice.customer_id,  
sum(invoice.cost) 
FROM invoice 
GROUP BY 
invoice.customer_name, invoice.customer_id

这将为您提供与其他字段匹配的所有行。

Select customer_name, Customer_id, count(Shop_location) from
(
    SELECT  
        invoice.customer_name,  
        invoice.customer_id,  
        invoice.shop_location, 
        sum(invoice.cost) 
    FROM invoice 
    GROUP BY 
        invoice.customer_name, 
        invoice.customer_id,
        invoice.shop_location 
 )
 Group by customer_name, Customer_id
 Having    count(Shop_location) > 1

上面的查询将为您提供具有多个商店位置的客户名称和ID的组合

注:我不确定这是否是优化的