Question

我需要在映射表中为每个单元创建一个新的行号。请检查以下示例数据和预期结果。

Lines table
+--------+------------+------+------+
| FileId | linenumber | code | unit |
+--------+------------+------+------+
|      1 |          1 | A    | NULL |
|      1 |          2 | B    | NULL |
|      1 |          3 | C    | NULL |
+--------+------------+------+------+

map table
+------+------+
| code | unit |
+------+------+
| A    | c1   |
| A    | c2   |
| B    | c3   |
| B    | c4   |
| B    | c5   |
+------+------+

expected result
+--------+------------+------+------+
| FileId | Linenumber | code | unit |
+--------+------------+------+------+
|      1 |          1 | A    | c1   |
|      1 |          2 | B    | c3   |
|      1 |          4 | A    | c2   |
|      1 |          5 | B    | c4   |
|      1 |          6 | B    | c5   |
+--------+------------+------+------+

代码A有两个单位（c1和c2），单位c1将以行号1和c2的单位更新应该以行号作为新行插入到行表中最后一个可用的行号之后。所有代码都应执行相同的过程

我当前的方法

if object_id('tempdb..#lines') is not null drop table #lines
if object_id('tempdb..#map') is not null drop table #map
if object_id('tempdb..#Files') is not null drop table #Files
if object_id('tempdb..#Maptemp') is not null drop table #Maptemp

create table #lines(FileId int, linenumber int, code varchar(10), unit varchar(10))
create table #map(code varchar(10), unit varchar(10))
insert into #lines values (1,1,'A',null), (1,2,'B',null),(1, 3,'C',null)
insert into #map values ('A','c1'),('A','c2'),('B','c3'),('B','c4'),('B','c5')

select FileId, MaxLinenum = max(linenumber) into #Files
    from #lines
    group by FileId

select row_number()over(partition by code order by (select null)) Rn,* into #Maptemp
    from #map

select l.FileId,l.Linenumber,l.code, m.unit
    from #lines l 
    inner join #Files f on l.FileId = f.FileId
    inner join #Maptemp m on m.code = l.code 
    where m.rn = 1
union all
select l.FileId, f.MaxLinenum +row_number()over(partition by f.FileId order by (select null)),l.code, m.unit
    from #lines l 
    inner join #Files f on l.FileId = f.FileId
    inner join #Maptemp m on m.code = l.code 
    where m.rn > 1

它工作正常，但是我觉得我为此做的编码很少。那么有没有更好的方法来实现这一目标？

Answer 1

这是我的尝试。您可能需要根据实际架构进行一些更改。

DECLARE @MAXLINE INT = (SELECT MAX(linenumber) FROM #lines)

SELECT L.FileId
    ,CASE WHEN M.SNO = 1 THEN L.linenumber
        ELSE 
            @MAXLINE + ROW_NUMBER() OVER (PARTITION BY CASE WHEN M.SNO<>1
                THEN 1 END ORDER BY M.CODE ,M.UNIT)
        END LINE_NUMBER
, M.code
, M.unit
FROM #lines L
INNER JOIN
(
    SELECT ROW_NUMBER() OVER(PARTITION BY CODE ORDER BY(UNIT)) SNO,*
    FROM #map
)M ON L.code = M.code

结果：

FileId  LINE_NUMBER code    unit
1       1           A       c1
1       2           B       c3
1       4           A       c2
1       5           B       c4
1       6           B       c5

Answer 2

它可能没有您想要的那么简单。无论如何都将其发布。

DECLARE @MaxLine INT;

SELECT @MaxLine = MAX(LineNumber)
FROM   lines;


IF OBJECT_ID('tempdb..#temp') IS NOT NULL
    DROP TABLE #temp;

SELECT   l.fileId ,
         l.linenumber ,
         l.code ,
         MIN(m.unit) AS unit
INTO     #temp
FROM     #Lines l
         JOIN #map m ON l.code = m.code
GROUP BY l.fileId ,
         l.linenumber ,
         l.code;

SELECT *
FROM   #temp
UNION
SELECT l.fileId ,
       @MaxLine + ROW_NUMBER() OVER ( PARTITION BY l.fileId
                                      ORDER BY l.code ) ,
       l.code ,
       m.unit
FROM   #LINES l
       JOIN #map m ON l.code = m.code
       LEFT JOIN #temp t ON l.code = t.code
                            AND m.unit = t.unit
WHERE  t.code IS NULL;

Answer 3

似乎想要：

select m.*,
       coalesce(l.linenumber,
                c.cnt + row_number() over (partition by l.linenumber order by m.linenumber)
               ) as new_linenumber
from (select m.*,
             row_number() over (partition by code order by linenumber) as seqnum
      from #map m
     ) m left join
     #lines l
     on l.code = m.code and m.seqnum = 1 cross join
     (select count(*) as cnt from #lines) c;

也就是说，新的行号是：

linenumber表中的行号-每个代码的首次出现。
基于不匹配的行号加上linenumber中的计数的序列号。

Answer 4

我会使用first_value()函数：

with t as (
     select l.fileid, l.code, m.unit, (case when f_value = m.unit then l.linenumber end) as lines, cnt.tcnt 
     from #lines l inner join
          (select *, first_value(unit) over (partition by code order by unit) as f_value
           from #map
          ) m
          on m.code = l.code cross join
         (select count(*) tcnt from #lines) cnt
)

select fileid, code, unit, 
       coalesce(lines, 
                tcnt + sum(case when lines is null then 1 end) over (order by unit)
               ) as linenumber
from t;

为每个映射生成新的行号

4 个答案: