Question

我在SQL Server中有一个查询，该查询提供了如下所述的根据AGE和SEX进行策略计数。

SELECT 
    PLYMMRAGE as AGE,
    MMRSEX as SEX,
    COUNT(PLYNO) AS POLICYCOUNT
FROM 
    ADMGMPLYMSR 
GROUP BY
    PLYMMRAGE, MMRSEX
ORDER BY 
    MMRSEX DESC, PLYMMRAGE

此查询的输出是：

AGE   SEX    POLICYCOUNT
------------------------
2     M      10
4     M       9
5     M       6
8     M       0
1     F       4
2     F       6
4     F       0

但是我希望即使年龄不存在，该行也应该显示所有年龄段，政策计数为0到10岁。

    AGE   SEX    POLICYCOUNT
   -------------------------
    1     M       0
    2     M      10
    3     M       0      
    4     M       9
    5     M       6
    6     M       0
    7     M       0
    8     M       0
    9     M       0
    10    M       0
    1     F       4
    2     F       6
    4     F       0

以此类推。

如果该行的年龄不存在，如何插入计数为零的数据？即使使用程序也可以

Answer 1

您可以同时使用LEFT JOIN和coalesce

with ADMGMPLYMSR( PLYMMRAGE, MMRSEX, PLYNO ) as
(
 select 2,'M',10 union all
 select 4,'M', 9 union all
 select 5,'M', 6 union all
 select 8,'M', 0 union all     
 select 1,'M', 4 union all
 select 2,'M', 6 union all
 select 4,'M', 0     
), t AS (
    SELECT 1 AS n
    UNION ALL
    SELECT n+1 FROM t WHERE n+1<=10
)
SELECT COALESCE(PLYMMRAGE,n) as AGE, COALESCE(MMRSEX,'M') as SEX, 
       COUNT(PLYNO) AS POLICYCOUNT
  FROM t 
  LEFT JOIN ADMGMPLYMSR ON PLYMMRAGE = n
 GROUP BY coalesce(PLYMMRAGE,n), MMRSEX
 ORDER BY coalesce(MMRSEX,'M') DESC, coalesce(PLYMMRAGE,n);

Demo

如何在SQL查询中实现序列

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