Få RÆKKER som KOLONNER (SQL Server dynamisk PIVOT-forespørgsel)

Det, du prøver at gøre, kaldes en PIVOT . Der er to måder at gøre dette på, enten med en statisk pivot eller en dynamisk pivot.

Statisk pivot - det er her, du skal hardkode rækkernes værdier, der skal transformeres til kolonner (se SQL-fil med demo):

select ws_id,
  start_date,
  end_date,
  IsNull([100.00], 0) [100.00],
  IsNull([50.00], 0) [50.00],
  IsNull([20.00], 0) [20.00],
  IsNull([10.00], 0) [10.00],
  IsNull([5.00], 0) [5.00],
  IsNull([1.00], 0) [1.00]
from 
(
  select ws.ws_id,
    ws.start_date,
    ws.end_date,
    cd.name,
    cbw.qty
  from workshift ws
  left join currency_by_workshift cbw
    on ws.ws_id = cbw.ws_id
  left join currency_denom cd
    on cbw.cd_id = cd.cd_id
) x
pivot
(
  sum(qty)
  for name in ([100.00], [50.00], [20.00], [10.00], [5.00], [1.00])
) p

Dynamisk pivot er det sted, hvor kolonnerne bestemmes ved kørsel (se SQL-fiffel med demo):

DECLARE @cols AS NVARCHAR(MAX),
    @query  AS NVARCHAR(MAX),
    @colsPivot AS NVARCHAR(MAX)

select @colsPivot = 
  STUFF((SELECT ', IsNull(' + QUOTENAME(rtrim(name)) +', 0) as ['+ rtrim(name)+']' 
                    from currency_denom
                   GROUP BY name
                   ORDER BY cast(name as decimal(10, 2)) desc
            FOR XML PATH(''), TYPE
            ).value('.', 'NVARCHAR(MAX)') 
        ,1,1,'')

select @cols = STUFF((SELECT distinct ', ' + QUOTENAME(name)
                    from currency_denom
            FOR XML PATH(''), TYPE
            ).value('.', 'NVARCHAR(MAX)') 
        ,1,1,'')


set @query 
      = 'SELECT ws_id, start_date, end_date,' + @colsPivot + ' from 
         (
            select ws.ws_id,
              ws.start_date,
              ws.end_date,
              cd.name,
              cbw.qty
            from workshift ws
            left join currency_by_workshift cbw
              on ws.ws_id = cbw.ws_id
            left join currency_denom cd
              on cbw.cd_id = cd.cd_id
         ) x
         pivot 
         (
            sum(qty)
            for name in (' + @cols + ')
         ) p '

execute(@query)

Begge versioner vil give de samme resultater.