SQL過濾器最低價格

Question

我有價格數據的一個巨大的表，用下面的列

source, product, term, miles, price 

的數據看起來是這樣

LL, PH, 3, 10000, 100.00 
BA, PH, 3, 10000, 200.00 
LL, CH, 3, 10000, 300.00 
BA, CH, 3, 10000, 400.00 

我需要創建一個查詢來篩選行以僅顯示每個唯一來源/產品/術語/英里組合的最低價格的行。所以在上面的例子中，我想結束：

LL, PH, 3, 10000, 100.00 
BA, PH, 3, 10000, 200.00 

任何幫助表示讚賞。謝謝。

Answer 1

您可以使用ROW_NUMBER()本：

SQL Fiddle

SELECT 
    source, product, term, miles, price 
FROM(
    SELECT *, 
     RN = ROW_NUMER() OVER(PARTITION BY source, product, term, miles ORDER BY price) 
    FROM [your_table] 
)t 
WHERE RN = 1 

或按編碼器代碼的評論，你可以使用MIN()和GROUP BY：

SQL Fiddle

SELECT 
    source, product, term, miles, price = MIN(price) 
FROM [your_table] 
GROUP BY source, product, term, miles 

Answer 2

select source, product, term, miles, price 
from tablename t1 
where not exists (select 1 from tablename t2 
        where t1.source = t2.source 
        and t2.price < t1.price) 

如果你想以最低的價格源/產品連續技，增加產品的分選的條件：

select source, product, term, miles, price 
from tablename t1 
where not exists (select 1 from tablename t2 
        where t1.source = t2.source 
        and t1.product = t2.product 
        and t2.price < t1.price) 

使用 NOT EXISTS到沒有更低的價格存在相同的源返回行

等

如果有一條領帶，兩行都會返回！

Answer 3

SELECT 
    source, product, term, miles, MIN(price) AS price 
FROM [table_name] 
GROUP BY source, product, term, miles