Question

我有一个包含2列table1和toypattern的表格additionalcolor}：

表1

toypattern  additionalcolor
FL38        orange
FL38        yellow
LF66        grey
LF66        black

现在我需要编写一个查询来显示toypattern列，1st color列和2nd color列。我需要显示最多5个additionalColor选项

期望的输出：

toypattern  1st color   2nd color     3rd color   4th color   5th color
  FL38        orange      yellow
  LF66        grey        black

如何编写这样的SQL查询？

Answer 1

试试这些：

;with cte as
(select toypattern, additionalcolor,
  row_number() over(partition by toypattern order by additionalcolor) As rn
from Table1)
select toypattern, 
  max(case when rn = 1 then additionalcolor end) as additionalcolor1,
  max(case when rn = 2 then additionalcolor end) as additionalcolor2
from cte
group by toypattern

返回：

toypattern  additionalcolor1    additionalcolor2
FL38        Orange              Yellow
LF66        Black               Grey

这样做的缺点是你需要为新的附加颜色添加新的MAX（...）行。

////

另一种解决方案是将其他颜色设为CSV：

SELECT DISTINCT T1.toypattern,
STUFF((SELECT TOP 100 PERCENT ',' + s2.additionalcolor FROM Table1 AS s2 WHERE s2.toypattern = T1.toypattern ORDER BY ',' + s2.additionalcolor FOR XML PATH('')), 1, 1, '') AS Colours
FROM Table1 AS T1
ORDER BY T1.toypattern

返回：

toypattern  Colours
FL38    Orange,Yellow
LF66    Black,Grey

希望这有帮助。

Answer 2

确定。不确定这个问题是否与这个问题有关（http://stackoverflow.com/questions/11070509/sql-query-issue-on-left-join）：

但是这里有一个可能就是你所追求的解决方案 - 拿了一些03Usr的代码（特别是row_number并添加了旋转）：

;with cte as
(select toypattern, additionalcolor,
  rowno =  row_number() over(partition by toypattern order by additionalcolor)
from Table1)
SELECT
  ToyPattern
  --, ToyName
  , 'color 1' = [1]
  , 'color 2' = [2]
  , 'color 3' = [3]
  , 'color 4' = [4]
  , 'color 5' = [5]
FROM (  
  SELECT
  ToyPattern
  --, ToyName
  , rowno
  , additionalcolor
  FROM
    cte
) AS tac PIVOT (
  MAX (additionalcolor) FOR rowno in ([1],[2],[3],[4],[5])
) AS PivotTable

Answer 3

SELECT 
   first.toypattern,
   first.additionalColor,
   second.additionalColor
FROM
   Table1 first
   INNER JOIN Table2 second ON first.toypattern = second.toypattern
WHERE
   first.additionalColor < second.additionalColor

问题是，如果每个模式有两种以上的颜色，你会得到几个匹配。

编辑：这并没有真正找回搜索超过2种颜色时可能希望获得的结果。但是，鉴于此答案附有评论，我不会删除它。

Answer 4

您使用的是什么Sql Server版本？（我无法添加注释）像上面发布的那样的Pivot将是最好的，但是如果您使用的是旧的Sql Server版本（如2000），您可以使用CURSOR执行此操作：

drop table #temp
create table #temp
(
   toypattern varchar(20),
   additionalcolor1 varchar(20),
   additionalcolor2 varchar(20),
   additionalcolor3 varchar(20),
   additionalcolor4 varchar(20),
   additionalcolor5 varchar(20)
)

declare @toypattern as varchar(20)
declare @additionalcolor as varchar(20)     
declare @Counter integer 
declare @StrSql varchar(200)    
declare @LastToyPattern as varchar(20)

set @LastToyPattern = ''

declare MyCursor cursor for  select toypattern, additionalcolor from table1 order by toypattern
open MyCursor
fetch next from MyCursor into @toypattern, @additionalcolor 

   while @@fetch_status = 0     
   begin
      if (@LastToyPattern <> @toypattern)
      begin
         if (@LastToyPattern <> '') 
         begin
            set @StrSql = @StrSql + replicate(',null', 5 - @Counter)    
            exec(@StrSql)
         end
         set @Counter = 0
         set @StrSql = 'insert into #temp select ''' + @toypattern + ''''
      end
      set @StrSql = @StrSql + ', ''' + @additionalcolor + ''''  
      set @Counter = @Counter + 1
      set @LastToyPattern = @toypattern
      fetch next from MyCursor into @toypattern, @additionalcolor
   end
set @StrSql = @StrSql + replicate(',null', 5 - @Counter)
exec(@StrSql)
close MyCursor
deallocate MyCursor
select * from #temp

SQL Server：列到行

4 个答案: