Question

好的，所以我没有得到任何合法的错误或任何东西，但我试图得到它，以便我可以计算一个州在两个单独的表中列出的次数。我想要的所有状态都会出现，但我知道在某些状态下应该有多个值，但是每个COUNT值都会导致值为1.这是我能解决的问题吗？

SELECT shipping_address_state,
   COUNT(shipping_address_state) OVER (PARTITION BY shopper_account_id)
FROM orders 
WHERE shipping_address_country IN ('USA', 'Canada', 'Mexico')
UNION
SELECT vendor_state,
   COUNT(vendor_state) OVER (PARTITION BY vendor_id)
FROM vendor
WHERE vendor_country IN ('USA', 'Canada', 'Mexico')

修改

所以我接受了一些建议，然后将其改为Union all。我还将DISTINCT添加到SELECT vendor_state和shipping_address_state部分。它现在摆脱了州名列中的所有重复，但计数仍然是1.如果没有DISTINCT关键字，重复的状态会显示，但是作为单独的数据行（如宾夕法尼亚州将显示3次，但每个计数为1）。这就是现在的样子。有人知道为什么COUNT关闭了吗？

SELECT DISTINCT vendor_state "State",
   COUNT(vendor_state) OVER (PARTITION BY vendor_id) "Count"
FROM vendor
WHERE vendor_country IN ('USA', 'Canada', 'Mexico')
UNION ALL
SELECT DISTINCT shipping_address_state "State",
   COUNT(shipping_address_state) OVER (PARTITION BY shopper_account_id) "Count"
FROM orders 
WHERE shipping_address_country IN ('USA', 'Canada', 'Mexico')

修改

有趣的是，我解决了COUNT问题的很大一部分。我只是改变了PARTITION BY子句，这样它就可以实现PARTITION BY。现在它们被正确计算，但由于它们位于两个表中，因此State列中仍然存在重复值。每个列只计算它在该表中仅显示的次数。我尝试将它改回UNION而不是UNION ALL，但它并没有改变任何东西。让我们看看是否可以做到这一点！

SELECT DISTINCT vendor_state "State",
   COUNT(vendor_state) OVER (PARTITION BY vendor_state) "Count"
FROM vendor
WHERE vendor_country IN ('USA', 'Canada', 'Mexico')
UNION ALL
SELECT DISTINCT shipping_address_state "State",
   COUNT(shipping_address_state) OVER (PARTITION BY shipping_address_state) "Count"
FROM orders 
WHERE shipping_address_country IN ('USA', 'Canada', 'Mexico')
ORDER BY "State"

Answer 1

更改UNION

的UNION ALL

UNION从结果集中删除重复的行。但UNION ALL显示结果集。

因此，在使用UNION ALL而不是UNION

时，您可以获得更好的效果

Answer 2

您应该将UNION更改为UNION，还要为count列设置一个名称，如下所示：

SELECT shipping_address_state,
   COUNT(shipping_address_state) OVER (PARTITION BY shopper_account_id) cnt
FROM orders 
WHERE shipping_address_country IN ('USA', 'Canada', 'Mexico')
UNION ALL
SELECT vendor_state,
   COUNT(vendor_state) OVER (PARTITION BY vendor_id) cnt
FROM vendor
WHERE vendor_country IN ('USA', 'Canada', 'Mexico')

UNIONed表不计算所有值

2 个答案: