CÓ NHIỀU CHĂN NUÔI? Cần tính theo giờ mỗi tháng

Một cách để làm điều đó

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

hoặc với 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

Đầu ra mẫu cho cả hai truy vấn:

| 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 |
...

Đây là SQLFiddle demo (sử dụng CASE )
Đây là SQLFiddle demo (sử dụng PIVOT )