Split rows into 12 columns

问题

I have a table with, say, 1000 rows. One of those columns is URL.

So, select URL from table.

However I want to display 12 URLs per row. The reason is that we are publishing work for people to do online and they will review 12 websites at a time.

So in this case we would have about 90 rows being output, each having 12 columns (except the last row which will be short a few).

Is there a straightforward way to do this? Is this a case for pivot or some other function?

回答1:

Simple example with dynamic PIVOT

CREATE TABLE dbo.Url
 (
  Id int IDENTITY,
  url nvarchar(max)
  )    

INSERT dbo.Url
VALUES ('http://www.url1.com'),
       ('http://www.url2.com'),
       ('http://www.url3.com'),
       ('http://www.url4.com')

DECLARE @cols AS nvarchar(MAX),
        @query AS nvarchar(MAX)

SELECT @cols = STUFF((SELECT DISTINCT ',' + QUOTENAME(ROW_NUMBER() OVER (ORDER BY Url))
                      FROM dbo.url
                      GROUP BY Url
                      FOR XML PATH(''), TYPE
                      ).value('.', 'NVARCHAR(MAX)'), 1, 1, '')

SET @query = 'SELECT' + @cols + ' FROM
      (
       SELECT Id, url
       FROM dbo.url
       ) x
       PIVOT
       (
        MAX(url)
        FOR Id IN (' + @cols + ') 
        ) p '
EXECUTE(@query)

回答2:

Here's online solution. It may looks a little complicated, though

declare @Temp_URLS table (URL nvarchar(128))
declare @Temp_Reviewers table (Name nvarchar(128))

insert into @Temp_Reviewers (Name)
select top 5
    'Reviewer' + 
    right('0000' + 
cast(row_number() over (order by number) as nvarchar(128)), 4)  
from master.dbo.spt_values

insert into @Temp_URLS (URL)
select top 30 
    'http://URL' + 
    right('0000' + 
    cast(row_number() over (order by number) as nvarchar(128)), 4) + '.com'
from master.dbo.spt_values

select
    Name,
    [1], [2], [3], [4], [5], [6], [7], [8], [9], [10], [11], [12]
from 
(
    select TT.Name, row_number() over (order by TT.Name asc) as RowNum
    from @Temp_Reviewers as TT
) as R
    outer apply
    (
        select top 12 TT.URL, row_number() over (order by TT.URL) as RowNum
    from 
    (
        select TTT.URL, 1 + row_number() over (order by TTT.URL asc) / 12 as RowNum
    from @Temp_URLS as TTT
    ) as TT
        where TT.RowNum = R.RowNum
    ) as CALC
pivot
(
    min(CALC.URL)
    for CALC.RowNum in
        ([1], [2], [3], [4], [5], [6], [7], [8], [9], [10], [11], [12])
) as PVT

Here's solution without Pivot and Row_Number

declare @Temp_URLS table (URL nvarchar(128), csikey int identity(1, 1))

insert into @Temp_URLS (URL)
select top 30 
    'http://URL' + 
    right('0000' + 
    cast(row_number() over (order by number) as nvarchar(128)), 4) + '.com'
from master.dbo.spt_values

select
    A.RowNum1,
    min(case when A.RowNum2 = 1 then A.URL else null end) as [1],
    min(case when A.RowNum2 = 2 then A.URL else null end) as [2],
    min(case when A.RowNum2 = 3 then A.URL else null end) as [3],
    min(case when A.RowNum2 = 4 then A.URL else null end) as [4],
    min(case when A.RowNum2 = 5 then A.URL else null end) as [5],
    min(case when A.RowNum2 = 6 then A.URL else null end) as [6],
    min(case when A.RowNum2 = 7 then A.URL else null end) as [7],
    min(case when A.RowNum2 = 8 then A.URL else null end) as [8],
    min(case when A.RowNum2 = 9 then A.URL else null end) as [9],
    min(case when A.RowNum2 = 10 then A.URL else null end) as [10],
    min(case when A.RowNum2 = 11 then A.URL else null end) as [11],
    min(case when A.RowNum2 = 12 then A.URL else null end) as [12]
from
(
    select
        T1.csikey, T1.URL,
        count(T2.csikey) / 12 + 1 as RowNum1,
        count(T2.csikey) % 12 + 1 as RowNum2
    from @Temp_URLS as T1
        left outer join @Temp_URLS as T2 on T2.csikey < T1.csikey
group by T1.csikey, T1.URL
) as A
group by A.RowNum1

回答3:

Please try below query, it works in Oracle 11G:

SELECT * FROM(
  SELECT URL,
    CAST(FLOOR((NUM+2)/3) AS INT) AS Row_Num,
    MOD(NUM+2, 3)+1 AS OrderNum
  FROM(
      SELECT 
        ROW_NUMBER() OVER (ORDER BY URL) as NUM, URL
      FROM 
        TBL_URL
  )T1
)T2 PIVOT (MIN(URL) FOR OrderNum IN ('1' AS "1", '2' AS "2", '3' AS "3"));

来源：https://stackoverflow.com/questions/12890467/split-rows-into-12-columns

标签

sql

pivot