SQL选择计数最高的行

我试图根据两个字段仅选择计数最高（）的行

首先，我有一个查询，它给我一个特定的ITEM-SUPPLIER组合在我的表中出现了多少次的值

select itemid, ordersupplierid, COUNT(OrderSupplierId) AS SupCount from purchaseorderline
group by itemid, ordersupplierid
order by ItemID

在结果中，我有：

itemid   | ordersupplierid | SupCount
15850    |  579            |  1
15850    |  587            |  3
15850    |  605            |  2
15851    |  616            |  5
15852    |  579            |  1
15852    |  587            |  2
15854    |  616            |  11
15855    |  616            |  1

因此，从那里我只需要获得行：

itemid   | ordersupplierid | SupCount
15850    |  587            |  3
15851    |  616            |  5
15852    |  587            |  2
15854    |  616            |  11
15855    |  616            |  1

正如在ItemId-OrderSupplierId组合中一样，SupCount最高

---

有人知道怎么做吗？非常感谢。

您可以使用窗口功能：

select itemid, ordersupplierid, supcount
from (select itemid, ordersupplierid, count(*) AS SupCount,
             max(count(*)) over (partition by itemid) as maxcount
      from purchaseorderline
      group by itemid, ordersupplierid
     ) io
where supcount = maxcount
order by ItemID;

如果存在连接，则将返回所有匹配的行。如果您只需要一行（即使有结），则可以使用

row\u number（）

：

---

我建议使用窗口功能：

WITH cte AS(
  select itemid, ordersupplierid, COUNT(OrderSupplierId) AS SupCount
  from purchaseorderline
  group by itemid, ordersupplierid
  order by ItemID
),
cteFilter AS(
SELECT itemid, ordersupplierid, SupCount, ROW_NUMBER() OVER (PARTITION BY itemid ORDER BY SupCount DESC) rn
  FROM cte
)
SELECT itemid, ordersupplierid, SupCount
  FROM cteFilter
  WHERE rn = 1

WITH cte AS(
  select itemid, ordersupplierid, COUNT(OrderSupplierId) AS SupCount
  from purchaseorderline
  group by itemid, ordersupplierid
  order by ItemID
),
cteFilter AS(
SELECT itemid, ordersupplierid, SupCount, ROW_NUMBER() OVER (PARTITION BY itemid ORDER BY SupCount DESC) rn
  FROM cte
)
SELECT itemid, ordersupplierid, SupCount
  FROM cteFilter
  WHERE rn = 1