PIVOTS multiples ? Besoin de compter par heure par mois

Une façon de le faire

WITH hour_list AS (
  SELECT 0 hour
  UNION ALL
  SELECT hour + 1 FROM hour_list WHERE hour < 23
)
SELECT h.hour,
       COALESCE(jan, 0) jan,
       COALESCE(feb, 0) feb,
       COALESCE(mar, 0) mar,
       COALESCE(apr, 0) apr,
       COALESCE(may, 0) may,
       COALESCE(jun, 0) jun,
       COALESCE(jul, 0) jul,
       COALESCE(aug, 0) aug,
       COALESCE(sep, 0) sep,
       COALESCE(oct, 0) oct,
       COALESCE(nov, 0) nov,
       COALESCE(dec, 0) dec
  FROM hour_list h LEFT JOIN
(
  SELECT DATEPART(HOUR, logtime) hour, 
         SUM(CASE WHEN DATEPART(MONTH, logtime) =  1 THEN 1 END) jan,
         SUM(CASE WHEN DATEPART(MONTH, logtime) =  2 THEN 1 END) feb,
         SUM(CASE WHEN DATEPART(MONTH, logtime) =  3 THEN 1 END) mar,
         SUM(CASE WHEN DATEPART(MONTH, logtime) =  4 THEN 1 END) apr,
         SUM(CASE WHEN DATEPART(MONTH, logtime) =  5 THEN 1 END) may,
         SUM(CASE WHEN DATEPART(MONTH, logtime) =  6 THEN 1 END) jun,
         SUM(CASE WHEN DATEPART(MONTH, logtime) =  7 THEN 1 END) jul,
         SUM(CASE WHEN DATEPART(MONTH, logtime) =  8 THEN 1 END) aug,
         SUM(CASE WHEN DATEPART(MONTH, logtime) =  9 THEN 1 END) sep,
         SUM(CASE WHEN DATEPART(MONTH, logtime) = 10 THEN 1 END) oct,
         SUM(CASE WHEN DATEPART(MONTH, logtime) = 11 THEN 1 END) nov,
         SUM(CASE WHEN DATEPART(MONTH, logtime) = 12 THEN 1 END) dec
    FROM somelog (NOLOCK)
   GROUP BY DATEPART(HOUR, logtime)
) l 
    ON h.hour = l.hour

ou avec PIVOT

WITH hour_list AS (
  SELECT 0 hour
  UNION ALL
  SELECT hour + 1 FROM hour_list WHERE hour < 23
)
SELECT h.hour,
       COALESCE([1],  0) jan,
       COALESCE([2],  0) feb,
       COALESCE([3],  0) mar,
       COALESCE([4],  0) apr,
       COALESCE([5],  0) may,
       COALESCE([6],  0) jun,
       COALESCE([7],  0) jul,
       COALESCE([8],  0) aug,
       COALESCE([9],  0) sep,
       COALESCE([10], 0) oct,
       COALESCE([11], 0) nov,
       COALESCE([12], 0) dec
  FROM hour_list h LEFT JOIN 
(
  SELECT DATEPART(MONTH, logtime) month,
         DATEPART(HOUR, logtime) hour,
         COUNT(*) log_count
    FROM somelog (NOLOCK)
   GROUP BY DATEPART(MONTH, logtime), DATEPART(HOUR, logtime)
) s
PIVOT
(
  SUM(log_count) FOR month IN([1],[2],[3],[4],[5],[6],[7],[8],[9],[10],[11],[12])
) p
    ON h.hour = p.hour

Exemple de résultat pour les deux requêtes :

| HOUR | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC |
|------|-----|-----|-----|-----|-----|-----|-----|-----|-----|-----|-----|-----|
|    0 |   2 |   0 |   0 |   0 |   0 |   0 |   0 |   0 |   0 |   0 |   0 |   0 |
|    1 |   1 |   0 |   0 |   0 |   0 |   0 |   0 |   0 |   0 |   0 |   0 |   0 |
|    2 |   0 |   1 |   0 |   0 |   0 |   0 |   0 |   0 |   0 |   0 |   0 |   0 |
|    3 |   0 |   0 |   1 |   0 |   0 |   0 |   0 |   0 |   0 |   0 |   0 |   0 |
|    4 |   0 |   0 |   0 |   1 |   0 |   0 |   0 |   0 |   0 |   0 |   0 |   0 |
...

Voici SQLFiddle démo (en utilisant CASE )
Voici SQLFiddle démo (en utilisant PIVOT )