SQL子查询问题

Question

我的问题是检索出售每个商品的商店数量超过平均市场价格;

SELECT SHOP_NAME, Trade_Name 
FROM SELL_ITEM f 
WHERE PRICE > 
    (SELECT 
    AVG(PRICE) 
    FROM SELL_ITEM s 
    WHERE f.Trade_Name = s.Trade_Name 
    GROUP BY TRADE_NAME); 

该查询返回我所有的商店，出售项目>高于市场平均价格，但我怎么能过滤掉那些不是为每个项目？

Answer 1

编辑...（错过了一个细微的第一次）

SELECT shop_name FROM 
(
    SELECT shop_name, MIN(case when f.price > a.avg_price then 1 else 0 end) AS is_always_higher_than_avg 
    FROM SELL_ITEM f 
    INNER JOIN 
    (
     SELECT avg(price) AS avg_price, trade_name 
     FROM sell_item 
     GROUP BY trade_name 
    ) a 
    ON f.trade_name = a.trade_name 
    WHERE f.price > a.avg_price 
    GROUP BY shop_name 
) b 
WHERE is_always_higher_than_avg = 1