按年齡范圍划分的 SQL 組

Question

SQL 2005，我有一個包含“ages_c”列的表，我需要按年齡范圍對記錄進行分組。 這是我在這個網站上找到的查詢，它讓我在那里找到了 90%，但“group by”出錯了，*無效的列名“age_range”*

 select 
  case
   when age_c <18 then 'Under 18'
   when age_c between 18 and 24 then '18-24'
   when age_c between 25 and 34then '25-34'
 END as age_range, 
 Count(*) as count
 from contacts
 group by age_range
 order by age_range

當我按“age_c”分組和排序時，我的結果是：

  Under 18  1
  18-24 1
  18-24 1
  25-34 1

我想要的是：

 Under 18   1
  18-24 2      
  25-34 1

謝謝。

Answer 1

試試這種方式：

 SELECT SUM(CASE WHEN age_c < 18 THEN 1 ELSE 0 END) AS [Under 18],
        SUM(CASE WHEN age_c BETWEEN 18 AND 24 THEN 1 ELSE 0 END) AS [18-24],
        SUM(CASE WHEN age_c BETWEEN 25 AND 34 THEN 1 ELSE 0 END) AS [25-34]
 FROM contacts

Answer 2

按age_c ——age_range 不是物理列。 更具體地說，這樣做：

group by case
   when age_c <18 then 'Under 18'
   when age_c between 18 and 24 then '18-24'
   when age_c between 25 and 34then '25-34'
 END

由於age_range是一個age_range ， group by根本不知道它。 分組發生在計算列集之前。 您可以在其中使用別名的唯一子句是order by ，因為這是在計算列集后執行的唯一子句。

Answer 3

您不能按您在查詢中創建的列進行分組。 你必須這樣做：

SELECT count(*), * FROM 
(
select 
  case
   when age_c <18 then 'Under 18'
   when age_c between 18 and 24 then '18-24'
   when age_c between 25 and 34then '25-34'
 END as age_range 
 from contacts
) t
group by age_range
order by age_range

或 GROUP BY

case
       when age_c <18 then 'Under 18'
       when age_c between 18 and 24 then '18-24'
       when age_c between 25 and 34then '25-34'
END

Answer 4

如果您的數據庫支持FILTER WHERE語法，那么這可以以非常優雅的方式存檔：

SELECT COUNT(id) FILTER (WHERE (age < 18)) AS "Under 18",
       COUNT(id) FILTER (WHERE (age >= 18 AND age <= 24)) AS "18-24",
       COUNT(id) FILTER (WHERE (age >= 25 AND age <= 34)) AS "25-34"
FROM contacts

或者這個，如果不是：

SELECT count(CASE WHEN (age < 18) THEN id ELSE null END)                AS "Under_18",
       count(CASE WHEN (age >= 18 AND age <= 24) THEN id ELSE null END) AS "18-24",
       count(CASE WHEN (age >= 25 AND age <= 34) THEN id ELSE null END) AS "25-34"
FROM contacts

Answer 5

CASE WHEN DATEDIFF(YEAR, DateOfBirth, GETDATE()) BETWEEN 20 AND 29 THEN '20-29'

        WHEN DATEDIFF(YEAR, DateOfBirth, GETDATE()) BETWEEN 30 AND 39 THEN '30-39'

        WHEN DATEDIFF(YEAR, DateOfBirth, GETDATE()) BETWEEN 40 AND 49 THEN '40-49'

           WHEN DATEDIFF(YEAR, DateOfBirth, GETDATE()) BETWEEN 50 AND 59 THEN '50-59'


        ELSE '60 AND Older'

    END AS age_group_Frequency,

count (CASE WHEN DATEDIFF(YEAR, DateOfBirth, GETDATE()) BETWEEN 20 AND 29 THEN '20-29'

        WHEN DATEDIFF(YEAR, DateOfBirth, GETDATE()) BETWEEN 30 AND 39 THEN '30-39'

        WHEN DATEDIFF(YEAR, DateOfBirth, GETDATE()) BETWEEN 40 AND 49 THEN '40-49'

           WHEN DATEDIFF(YEAR, DateOfBirth, GETDATE()) BETWEEN 50 AND 59 THEN '50-59'


        ELSE '60 AND Older'

    END) AS age_group
       
     


  FROM

put your statement****

where

*****

  group by 
CASE WHEN DATEDIFF(YEAR, DateOfBirth, GETDATE()) BETWEEN 20 AND 29 THEN '20-29'

        WHEN DATEDIFF(YEAR, DateOfBirth, GETDATE()) BETWEEN 30 AND 39 THEN '30-39'

        WHEN DATEDIFF(YEAR, DateOfBirth, GETDATE()) BETWEEN 40 AND 49 THEN '40-49'

           WHEN DATEDIFF(YEAR, DateOfBirth, GETDATE()) BETWEEN 50 AND 59 THEN '50-59'


        ELSE '60 AND Older'

    END

Answer 6

那是您正在使用的實際代碼嗎？ 它看起來不像，因為您在 34 和 then 之間缺少一個空格。 該代碼會在 SQL 中出錯。 介意分享實際的未修改查詢嗎？

無論如何，您可以使用臨時表或嵌套查詢。

SELECT
 CASE
  WHEN age_c <18 THEN 'Under 18'
  WHEN age_c BETWEEN 18 AND 24 THEN '18-24'
  WHEN age_c BETWEEN 25 AND 34 THEN '25-34'
END AS age_range, 
INTO #TempAges
FROM contacts
ORDER BY age_c

SELECT COUNT(*) FROM #TempAges GROUP BY age_range

完成后不要忘記刪除臨時表