TSQL：我的 Partition By 做错了什么？

Question

ItemID | NumberOfUses | LastMaint | Partition
 0111          1           NULL         1

 0111          1         1/1/2015       2
 0111          2         1/1/2015       2
 0111          3         1/1/2015       2
 0111          4         1/1/2015       2
 0111          5         1/1/2015       2

 0111          1         4/1/2015       3
 0111          2         4/1/2015       3
 0111          3         4/1/2015       3

 0111          1         7/1/2015       4
 0111          2         7/1/2015       4
 0111          3         7/1/2015       4
 0111          4         7/1/2015       4
 0111          5         7/1/2015       4
 0111          6         7/1/2015       4 
 0111          7         7/1/2015       4 
 0111          8         7/1/2015       4 
 0111          9         7/1/2015       4

我想弄清楚的是如何使分区列看起来像上面那样。（我在不同的 groups/partitions 之间加了一个 space 只是为了方便看）。

我一直在尝试使用与以下查询接近的内容来执行此操作。我已经尝试了 ROW_NUMBER() OVER()

中几乎所有列的组合

SELECT [ItemID]
      ,[NumberOfUses]
      ,[LastMaintenance]
      ,ROW_NUMBER() OVER (PARTITION BY ?????????
                            ORDER BY ???????) [Partition]     
    FROM [ItemsHistory]

ORDER BY [Partition]

Answer 1

尝试 DENSE_RANK:

SELECT [ItemID]
      ,[NumberOfUses]
      ,[LastMaintenance]
      ,DENSE_RANK() OVER (PARTITION BY [ItemId] ORDER BY [LastMaintenance]) [Partition]     
FROM [ItemsHistory]
ORDER BY [ItemId], [Partition], [NumberOfUses]

TSQL：我的 Partition By 做错了什么？

TSQL: What am I doing wrong with my Partition By?

tsql

row-number

partition-by