如何与"row_number() over (partition by [Col] order by [Col])"相反

Question

我正在尝试合并数据表中的重复条目并给它们一个新数字。

下面是一个示例数据集（可运行的副本）

declare @tmpTable table
    (ID Varchar(1), 
     First varchar(4), 
     Last varchar(5), 
     Phone varchar(13),
     NonKeyField varchar(4))
insert into @tmpTable select 'A', 'John', 'Smith', '[phone]', 'ASDF'
insert into @tmpTable select 'B', 'John', 'Smith', '[phone]', 'GHJK'
insert into @tmpTable select 'C', 'Jane', 'Smith', '[phone]', 'QWER'
insert into @tmpTable select 'D', 'John', 'Smith', '[phone]', 'RTYU'
insert into @tmpTable select 'E', 'Bill', 'Blake', '[phone]', 'BVNM'
insert into @tmpTable select 'F', 'Bill', 'Blake', '[phone]', '%^&*'
insert into @tmpTable select 'G', 'John', 'Smith', '[phone]', '!#RF'
select row_number() over (partition by First, Last, Phone order by ID) NewIDNum, *  
from @tmpTable order by ID

现在它给了我结果

NewIDNum             ID   First Last  Phone         NonKeyField
-------------------- ---- ----- ----- ------------- -----------
1                    A    John  Smith [phone] ASDF
2                    B    John  Smith [phone] GHJK
1                    C    Jane  Smith [phone] QWER
3                    D    John  Smith [phone] RTYU
1                    E    Bill  Blake [phone] BVNM
2                    F    Bill  Blake [phone] %^&*
4                    G    John  Smith [phone] !#RF

然而，这与我想要的相反，每当找到新的键组合时，NewIDNum都会重置其计数器。我希望所有相同的组合都具有相同的ID。因此，如果它按照我想要的方式运行，我会得到以下结果

NewIDNum             ID   First Last  Phone         NonKeyField
-------------------- ---- ----- ----- ------------- -----------
1                    A    John  Smith [phone] ASDF
1                    B    John  Smith [phone] GHJK
2                    C    Jane  Smith [phone] QWER
1                    D    John  Smith [phone] RTYU
3                    E    Bill  Blake [phone] BVNM
3                    F    Bill  Blake [phone] %^&*
1                    G    John  Smith [phone] !#RF

获得我想要的结果的正确方法是什么？

<小时 />

我没有在原始帖子中包含此要求：如果添加了更多行，我需要NewIDNum在后续运行此查询时为现有行生成相同的数字（假设所有新行将具有更高的 ID "值"如果在 ID 列上完成排序）

因此，如果在以后的日期完成了以下操作

insert into @tmpTable select 'H', 'John', 'Smith', '[phone]', '4321'
insert into @tmpTable select 'I', 'Jake', 'Jons', '[phone]', '1234'
insert into @tmpTable select 'J', 'John', 'Smith', '[phone]', '2345'

再次运行正确的查询将给出

NewIDNum             ID   First Last  Phone         NonKeyField
-------------------- ---- ----- ----- ------------- -----------
1                    A    John  Smith [phone] ASDF
1                    B    John  Smith [phone] GHJK
2                    C    Jane  Smith [phone] QWER
1                    D    John  Smith [phone] RTYU
3                    E    Bill  Blake [phone] BVNM
3                    F    Bill  Blake [phone] %^&*
1                    G    John  Smith [phone] !#RF
1                    H    John  Smith [phone] 4321
4                    I    Jake  Jons  [phone] 1234
1                    J    John  Smith [phone] 2345

Answer 1

您可以使用

dense_rank()：

dense_rank() over (order by First, Last, Phone) as NewIDNum

为了响应您的评论，您可以使用相同的(First, Last, Phone)组合对每组行的旧Id列的最小值进行排序：

select  *
from    (
        select  dense_rank() over (order by min_id) as new_id
        ,       *
        from    (
                select  min(id) over (
                            partition by First, Last, Phone) as min_id
                ,       *
                from    @tmpTable 
                ) as sub1
        ) as sub3
order by
        new_id

Answer 2

建立在@Andomar的原始答案之上——这将适用于您更新的需求（尽管这不太可能很好地扩展）

select
    DENSE_RANK() over (ORDER BY IdRank, First, Last, Phone) AS NewIDNum,
    ID,
    First,
    Last,
    Phone,
    NonKeyField
from
(
    select
        MIN(ID) OVER (PARTITION BY First, Last, Phone) as IdRank,
        *
    from
        @tmpTable
) as x
order by
    ID;

Answer 3

感谢安多玛的回答作为起点，我自己解决了

select sub1.rn, tt.*
from @tmpTable tt
inner join (
    select row_number() over (order by min(ID)) as rn, first, last, phone
    from @tmpTable
    group by first, last, phone
    ) as sub1 on tt.first = sub1.first and tt.last = sub1.last and tt.phone = sub1.phone

这会产生

rn                   ID   First Last  Phone         NonKeyField
-------------------- ---- ----- ----- ------------- -----------
1                    A    John  Smith [phone] ASDF
1                    B    John  Smith [phone] GHJK
1                    D    John  Smith [phone] RTYU
1                    G    John  Smith [phone] !#RF
1                    H    John  Smith [phone] 4321
1                    J    John  Smith [phone] 2345
2                    C    Jane  Smith [phone] QWER
3                    E    Bill  Blake [phone] BVNM
3                    F    Bill  Blake [phone] %^&*
4                    I    Jake  Jons  [phone] 1234

---

查看SQL执行计划，Adnomar的答案对于比我更大的数据集运行得更快。（53% 的执行时间与 47% 的执行时间，当彼此相邻运行并选中"包括实际执行计划"时。

Answer 4

这应该有效

select dense_rank() over (order by First, Last, Phone) NewIDNum, *  
from @tmpTable order by ID