SQL 查询不同并按雪花分组

Question

我想要完成的是获取给定 MPN 的所有记录，但是，我只想要来自 shpm 的最新 DeliveryDate 但考虑到 MAX函数需要在group by子句中，它不获取最新记录，它获取所有记录因为不同的DeliveryDate，它获取两条记录而不是一条记录，我怎么能实现这个？这是雪花。

这是我的SQL代码

SELECT
    MD.MPN,
    MD.LOTCODE,
    MD.DATECODE,
    SHIP.ITEMCODE AS SYSTEMPARTNUMBER, 
    SHIP.SERIALNUMBER AS SYSTEMSERIALNUMBER, 
    SHIP.CUSTOMERNAME, 
    SHIP.SHIPTOADDRESS AS ADDRESS,
    SUM(IFNULL(SHIP.QUANTITY,0)) AS QUANTITY,
    SHIP.DELIVERYDATE
FROM cunits UNITS
   JOIN unc UC ON UC.CHILDUNITID = UNITS.ID
   JOIN shpm SHIP ON SHIP.SERIALNUMBER = UC.SYSSN
   JOIN tsern SN ON SN.UNITID = UNITS.ID
   JOIN machined MD ON MD.SERIALNUMBER = SN.SERIALNUMBER     
WHERE --SYSTEMSERIALNUMBER = '001801055469' and 
MPN = 'XC0402A105KP5CNN-S'
GROUP BY MD.MPN,MD.LOTCODE,MD.DATECODE,SHIP.ITEMCODE,SHIP.SERIALNUMBER,SHIP.CUSTOMERNAME,SHIP.SHIPTOADDRESS

Answer 1

使用ROW_NUMBER()和QUALIFY:

SELECT MD.MPN, MD.LOTCODE, MD.DATECODE,
       SHIP.ITEMCODE AS SYSTEMPARTNUMBER, SHIP.SERIALNUMBER AS SYSTEMSERIALNUMBER, 
       SHIP.CUSTOMERNAME, SHIP.SHIPTOADDRESS AS ADDRESS,
       SUM(COALESCE(SHIP.QUANTITY, 0)) AS QUANTITY,
       SHIP.DELIVERYDATE
FROM cunits UNITS JOIN
     unc UC
     ON UC.CHILDUNITID = UNITS.ID JOIN
     shpm SHIP
     ON SHIP.SERIALNUMBER = UC.SYSSN JOIN
     tsern SN
     ON SN.UNITID = UNITS.ID JOIN
     machined MD
     ON MD.SERIALNUMBER = SN.SERIALNUMBER     
WHERE '001801055469' and MPN = 'XC0402A105KP5CNN-S'
GROUP BY MD.MPN, MD.LOTCODE, MD.DATECODE, SHIP.ITEMCODE, SHIP.SERIALNUMBER, SHIP.CUSTOMERNAME, SHIP.SHIPTOADDRESS
QUALIFY ROW_NUMBER() OVER (PARTITION BY MD.MPN, SHIP.SERIALNUMBER ORDER BY SHIP.SHIPDATE DESC) = 1;

每 MPN 行的 returns 这就是我对您的问题的解释。您可能还需要 PARTITION BY 中的其他列。

Answer 2

所以猜测一些数据来匹配 SQL

WITH cunits AS (
    SELECT * from values (1) v(id)
), unc AS (
    SELECT * FROM VALUES (1,'123') v(CHILDUNITID,SYSSN)
), shpm AS (
    SELECT * FROM VALUES ('a', '123', 10, '2020-02-01'),
       ('a', '123', 20, '2020-01-01') 
   v(ITEMCODE, SERIALNUMBER, QUANTITY, DELIVERYDATE)
), tsern AS (
    SELECT * FROM VALUES (1,'zxc') v(UNITID,SERIALNUMBER)
), machined as (
    SELECT * FROM VALUES ('zxc', 'XC0402A105KP5CNN-S') v(SERIALNUMBER, MPN)
)

并从示例中删除一些无关紧要的列

SELECT
    MD.MPN,
    SHIP.ITEMCODE AS SYSTEMPARTNUMBER, 
    SHIP.SERIALNUMBER AS SYSTEMSERIALNUMBER, 
    SUM(IFNULL(SHIP.QUANTITY,0)) AS QUANTITY,
    SHIP.DELIVERYDATE
FROM cunits UNITS
   JOIN unc UC ON UC.CHILDUNITID = UNITS.ID
   JOIN shpm SHIP ON SHIP.SERIALNUMBER = UC.SYSSN
   JOIN tsern SN ON SN.UNITID = UNITS.ID
   JOIN machined MD ON MD.SERIALNUMBER = SN.SERIALNUMBER     
WHERE 
MPN = 'XC0402A105KP5CNN-S'
GROUP BY MD.MPN,SHIP.ITEMCODE,SHIP.SERIALNUMBER;

现在必须将 SHIP.DELIVERYDATE 添加到 group by 子句中，否则此代码将永远运行，甚至忽略您不想看到 2020-01-01 数据的愿望

一旦你添加了你不想要的两行。

MPN SYSTEMPARTNUMBER    SYSTEMSERIALNUMBER  QUANTITY    DELIVERYDATE
XC0402A105KP5CNN-S  a   123 10  2020-02-01
XC0402A105KP5CNN-S  a   123 20  2020-01-01

Gordon 的解决方案，添加一个 QUALIFY

QUALIFY ROW_NUMBER() OVER (PARTITION BY MD.MPN, SHIP.SERIALNUMBER ORDER BY SHIP.DELIVERYDATE DESC) = 1;

正确地给出了答案，但是计算了所有的结果，然后 p运行ing 那些不想要的结果..取决于你的数据集大小和你的 shpm table，预过滤器的 CTE 可能会更好..

WITH cunits AS (
    SELECT * from values (1) v(id)
), unc AS (
    SELECT * FROM VALUES (1,'123') v(CHILDUNITID,SYSSN)
), shpm AS (
    SELECT * FROM VALUES ('a', '123', 10, '2020-02-01'),
       ('a', '123', 20, '2020-01-01') 
   v(ITEMCODE, SERIALNUMBER, QUANTITY, DELIVERYDATE)
), tsern AS (
    SELECT * FROM VALUES (1,'zxc') v(UNITID,SERIALNUMBER)
), machined as (
    SELECT * FROM VALUES ('zxc', 'XC0402A105KP5CNN-S') v(SERIALNUMBER, MPN)
), pre_filtered_shpm AS (
    select * from shpm
    QUALIFY ROW_NUMBER() OVER (PARTITION BY SERIALNUMBER ORDER BY DELIVERYDATE DESC) = 1
)
SELECT
    MD.MPN,
    SHIP.ITEMCODE AS SYSTEMPARTNUMBER, 
    SHIP.SERIALNUMBER AS SYSTEMSERIALNUMBER, 
    SUM(IFNULL(SHIP.QUANTITY,0)) AS QUANTITY,
    SHIP.DELIVERYDATE
FROM cunits UNITS
   JOIN unc UC ON UC.CHILDUNITID = UNITS.ID
   JOIN pre_filtered_shpm SHIP ON SHIP.SERIALNUMBER = UC.SYSSN
   JOIN tsern SN ON SN.UNITID = UNITS.ID
   JOIN machined MD ON MD.SERIALNUMBER = SN.SERIALNUMBER     
WHERE 
MPN = 'XC0402A105KP5CNN-S'
GROUP BY MD.MPN,SHIP.ITEMCODE,SHIP.SERIALNUMBER,SHIP.DELIVERYDATE;

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