Ruby on Rails：必须出现在GROUP BY子句中或用于聚合函数

Question

这是我的疑问。

ShopifyOrderLineItem.select("shopify_order_line_items.*, sum(amount) as total_price, sum(quantity) as total_quantity").where(:vendor_id => vendor_id).group("shopify_order_line_items.title")

我收到以下异常。

PG::GroupingError: ERROR:  column "shopify_order_line_items.id" must appear in the GROUP BY clause or be used in an aggregate function
LINE 1: SELECT shopify_order_line_items.*, sum(amount) as total_pric...

有什么建议吗？

我试过这个，但它没有用。

ShopifyOrderLineItem.select("shopify_order_line_items.*, count(shopify_order_line_items.id) as unique_ids, sum(amount) as total_price, sum(quantity) as total_quantity").where(:vendor_id => vendor_id).group("shopify_order_line_items.title")

Answer 1

如果要执行SUM或COUNT之类的聚合，则只能选择执行GROUP BY的列。

ShopifyOrderLineItem.select("shopify_order_line_items.title, count(shopify_order_line_items.id) as unique_ids, sum(amount) as total_price, sum(quantity) as total_quantity").where(:vendor_id => vendor_id).group("shopify_order_line_items.title")