如何为每个有条件的分区应用 row_number

Question

我想添加一个名为 PLRowNo 的列，它是每个凭证组中 PL actype 的行号。我还希望每个凭证编号的编号从 1 开始。

这是预期的结果

| id | voucherID | actype | PLRowNo |
|----|-----------| -------|---------|
| 1  | voucher01 | BS     |         |
| 2  | voucher01 | PL     | 1       |
| 3  | voucher01 | BS     |         |
| 4  | voucher01 | PL     | 2       |
| 5  | voucher01 | PL     | 3       |
| 6  | voucher01 | BS     |         |       
| 7  | voucher01 | PL     | 4       |
| 8  | voucher01 | BS     |         |
| 9  | voucher01 | PL     | 5       |
| 10 | voucher02 | PL     |         |
| 11 | voucher02 | PL     | 1       |
| 12 | voucher02 | BS     |         |
| 13 | voucher02 | PL     | 2       |

这是我试过的：

CREATE TABLE tbl_tmp (
    id int not null primary key,
    voucherID nvarchar(10) not null,
    actype nvarchar(10) not null
);

insert into tbl_tmp(id,voucherID, actype)
values (1,'voucher01', 'BS'),
        (2,'voucher01', 'PL'),
        (3,'voucher01', 'BS'),
        (4,'voucher01', 'PL'),
        (5,'voucher01', 'PL'),
        (6,'voucher01', 'BS'),
        (7,'voucher01', 'PL'),
        (8,'voucher01', 'BS'),
        (9,'voucher01', 'PL'),
        (10,'voucher02', 'PL'),
        (11,'voucher02', 'PL'),
        (12,'voucher02', 'BS'),
        (13,'voucher02', 'PL')

select *,0 as PLRowNo into #tmp from tbl_tmp
declare @id int set @id=0

update #tmp
set @id= case when actype ='PL' then @id+1   else 0 end,
 PLRowNo = case when actype='PL' then @id else 0 end

select * from #tmp

此查询的问题是，如果前一行的类型为“BS”，即使在同一个凭证分区中，它也会从 1 (id: 13) 开始计数。我想要一张优惠券内的延续。

这是错误的结果

| id | voucherID | actype | PLRowNo |
|----|-----------| -------|---------|
| 1  | voucher01 | BS     |         |
| 2  | voucher01 | PL     | 1       |
| 3  | voucher01 | BS     |         |
| 4  | voucher01 | PL     | 2       |
| 5  | voucher01 | PL     | 3       |
| 6  | voucher01 | BS     |         |       
| 7  | voucher01 | PL     | 4       |
| 8  | voucher01 | BS     |         |
| 9  | voucher01 | PL     | 5       |
| 10 | voucher02 | PL     |         |
| 11 | voucher02 | PL     | 1       |
| 12 | voucher02 | BS     |         |
| 13 | voucher02 | PL     | 1       |

Answer 1

请试试这个。

select *,    
CASE
    WHEN actype='PL' THEN CAST((select count(*) from tbl_tmp as t where actype='PL' and t.id<=tbl_tmp.id and  t.voucherID=tbl_tmp.voucherID )as VarChar(10))
    ELSE ''
END
as PLRowNo     
from tbl_tmp

Answer 2

您不需要临时表或，您可以只使用 ROW_NUMBER

SELECT *,
  PLRow_no = CASE WHEN actype = 'PL' THEN
    ROW_NUMBER() OVER (PARTITION BY actype, voucherID ORDER BY id) 
    END
FROM tbl_tmp
ORDER BY id;

db<>fiddle

如何为每个有条件的分区应用 row_number

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