如果通过 SQL 查询结果没有找到记录，则应为 0

我正在使用火鸟。我需要以下结果，但我没有得到我需要的结果。我尝试了以下查询。

SELECT 
  CASE EXTRACT(MONTH FROM pd.Date)
    WHEN 1 THEN 'January'
    WHEN 2 THEN 'February'
    WHEN 3 THEN 'March'
    WHEN 4 THEN 'April'
    WHEN 5 THEN 'May'
    WHEN 6 THEN 'June'
    WHEN 7 THEN 'July'
    WHEN 8 THEN 'August'
    WHEN 9 THEN 'September'
    WHEN 10 THEN 'October'
    WHEN 11 THEN 'November'
    WHEN 12 THEN 'December'
  END AS "MONTH",
  Count(distinct pd.numbers) AS "Count"       
FROM Power_D pd 
WHERE EXTRACT(YEAR FROM pd.Date) = '2016' 
AND pd.Name = 'Test' 
GROUP BY EXTRACT(MONTH FROM pd.Date)

对于下面这个查询结果。

February    330
March       212
April       178
May         222
June        487
July        695
August      433
September   757
October     1307
November    321
December    143

但我需要像下面这样。

January     0
February    330
March       212
April       178
May         222
June        487
July        695
August      433
September   757
October     1307
November    321
December    143

这是基于 @JNevill 评论的 MySQL/MariaDb 的可能解决方案

SELECT m.month_name, count(distinct pd.numbers) AS "Count"
FROM 
(
    SELECT 1 AS month, 'January' as month_name
    UNION ALL SELECT 2, 'February'
    UNION ALL SELECT 3, 'March'
    UNION ALL SELECT 4, 'April'
    UNION ALL SELECT 5, 'May'
    UNION ALL SELECT 6, 'June'
    UNION ALL SELECT 7, 'July'
    UNION ALL SELECT 8, 'August'
    UNION ALL SELECT 9, 'September'
    UNION ALL SELECT 10, 'October'
    UNION ALL SELECT 11, 'November'
    UNION ALL SELECT 12, 'December'
    
) m

LEFT JOIN 

(
    SELECT *    
    FROM Power_D 
    WHERE EXTRACT(YEAR FROM Date) = '2016' 
      AND Name = 'Test' 
      
) pd ON EXTRACT(MONTH FROM pd.Date) = m.month

GROUP BY m.month_name
ORDER BY m.month