sql - 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的数字。

这是一个示例数据集 ( runnable copy )

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', '(555)555-1234', 'ASDF'
insert into @tmpTable select 'B', 'John', 'Smith', '(555)555-1234', 'GHJK'
insert into @tmpTable select 'C', 'Jane', 'Smith', '(555)555-1234', 'QWER'
insert into @tmpTable select 'D', 'John', 'Smith', '(555)555-1234', 'RTYU'
insert into @tmpTable select 'E', 'Bill', 'Blake', '(555)555-0000', 'BVNM'
insert into @tmpTable select 'F', 'Bill', 'Blake', '(555)555-0000', '%^&*'
insert into @tmpTable select 'G', 'John', 'Smith', '(555)555-1234', '!#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 (555)555-1234 ASDF
2                    B    John  Smith (555)555-1234 GHJK
1                    C    Jane  Smith (555)555-1234 QWER
3                    D    John  Smith (555)555-1234 RTYU
1                    E    Bill  Blake (555)555-0000 BVNM
2                    F    Bill  Blake (555)555-0000 %^&*
4                    G    John  Smith (555)555-1234 !#RF

但这与我想要的相反，NewIDNum 每当发现新的按键组合时都会重置其计数器。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 (555)555-1234 ASDF
1                    B    John  Smith (555)555-1234 GHJK
2                    C    Jane  Smith (555)555-1234 QWER
1                    D    John  Smith (555)555-1234 RTYU
3                    E    Bill  Blake (555)555-0000 BVNM
3                    F    Bill  Blake (555)555-0000 %^&*
1                    G    John  Smith (555)555-1234 !#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:如果有更多行，我需要 NewIDNum 在后续运行此查询时为现有行生成相同的数字被添加(假设如果在 ID 列上完成排序，则所有新行将具有更高的 ID“值”)

因此，如果稍后完成以下操作

insert into @tmpTable select 'H', 'John', 'Smith', '(555)555-1234', '4321'
insert into @tmpTable select 'I', 'Jake', 'Jons', '(555)555-1234', '1234'
insert into @tmpTable select 'J', 'John', 'Smith', '(555)555-1234', '2345'

再次运行正确的查询将给出

NewIDNum             ID   First Last  Phone         NonKeyField
-------------------- ---- ----- ----- ------------- -----------
1                    A    John  Smith (555)555-1234 ASDF
1                    B    John  Smith (555)555-1234 GHJK
2                    C    Jane  Smith (555)555-1234 QWER
1                    D    John  Smith (555)555-1234 RTYU
3                    E    Bill  Blake (555)555-0000 BVNM
3                    F    Bill  Blake (555)555-0000 %^&*
1                    G    John  Smith (555)555-1234 !#RF
1                    H    John  Smith (555)555-1234 4321
4                    I    Jake  Jons  (555)555-1234 1234
1                    J    John  Smith (555)555-1234 2345

Answer 1

您可以使用dense_rank():

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

为了回复您的评论，您可以使用相同的(名字、姓氏、电话号码) 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