Kombinera flera rader till en rad

Du kan inte ha ett sådant dynamiskt antal kolumner, men du kan sammanfoga dina data i sträng:

select
    s.ItemID, s.Code, s.Name,
    stuff(
        (
            select ', ' + CAST(sv.SearchValueID AS VARCHAR)
            from ItemSearch as sv
            where sv.ItemID = s.ItemID
            for xml path(''), type
        ).value('.', 'nvarchar(128)')
    , 1, 2, '') as SearchValues
from Item as s;

eller så kan du pivotera rader med PIVOT command eller manuellt (Jag föredrar det senare tillvägagångssättet, det verkar bara mer flexibelt för mig, men pivot kan avsevärt minska mängden kod i vissa situationer ):

with cte as (
    select
        *,
        row_number() over(partition by sv.ItemID order by sv.SearchValueID) as row_num
    from ItemSearch as sv
)
select
    s.ItemID, s.Code, s.Name,
    max(case when sv.row_num = 1 then sv.SearchValueID end) as SearchValueID1,
    max(case when sv.row_num = 2 then sv.SearchValueID end) as SearchValueID2,
    max(case when sv.row_num = 3 then sv.SearchValueID end) as SearchValueID3,
    max(case when sv.row_num = 4 then sv.SearchValueID end) as SearchValueID4
from Item as s
    inner join cte as sv on sv.ItemID = s.ItemID
group by s.ItemID, s.Code, s.Name

Du kan också omvandla tidigare sats till dynamisk SQL så här:

declare @stmt nvarchar(max)

select
    @stmt = 
        isnull(@stmt + ',','') + 
        'max(case when sv.row_num = ' + cast(rn as nvarchar(max)) +
        ' then sv.SearchValueID end) as SearchValueID' + cast(rn as nvarchar(max))
from (
    select distinct row_number() over(partition by ItemID order by SearchValueID) as rn
    from ItemSearch
) as a

select @stmt = '
    with cte as (
        select
            *,
            row_number() over(partition by sv.ItemID order by sv.SearchValueID) as row_num
        from ItemSearch as sv
    )
    select
        s.ItemID, s.Code, s.Name,' + @stmt + '
    from Item as s
        inner join cte as sv on sv.ItemID = s.ItemID
    group by s.ItemID, s.Code, s.Name;'

exec dbo.sp_executesql @stmt = @stmt

sql fioldemo