Question

首先关闭：这里总SQL新手。不幸的是，我在截止日期前对我提出了这个要求。：/如果这是一个愚蠢的问题我很抱歉。

所以我有一个包含各种列的视图的数据库。它有两个我感兴趣的专栏： UserID 和年龄。

年龄以报告创建之日起的几天内存储报告的年龄。
UserID 是创建报告的用户。

该视图列出了用户的所有报告。

我需要做的是从现有视图中创建一个新表/视图，列出每个唯一用户，然后将其总文档分解为各个年龄组。所以列看起来像：

用户|| #rprts＆lt; 14天|| #rprts 14-17天|| #rps 18-28天|| #rps 29-44天|| #rprts 45+天

我知道我可以获得我想要的所有用户的集合：

SELECT DISTINCT [UserID] FROM [DB].[dbo].[DB_View]

我可以通过硬编码UserID＃来运行以下内容并获取我想要的新表/视图行：

SELECT DISTINCT 

    [UserID],
    (SELECT COUNT(*) FROM [DB].[dbo].[DB_View] WHERE (Age < 14) AND UserID = '9999') AS "Less Than 14 Days",
    (SELECT COUNT(*) FROM [DB].[dbo].[DB_View] WHERE (Age BETWEEN 14 AND 17) AND UserID = '9999') AS "14 to 17 Days",
    (SELECT COUNT(*) FROM [DB].[dbo].[DB_View] WHERE (Age BETWEEN 18 AND 28) AND UserID = '9999') AS "18 to 28 Days",
    (SELECT COUNT(*) FROM [DB].[dbo].[DB_View] WHERE (Age BETWEEN 29 AND 44) AND UserID = '9999') AS "29 to 44 Days",
    (SELECT COUNT(*) FROM [DB].[dbo].[DB_View] WHERE (Age >= 45) AND UserID = '9999') AS "Over 45 Days"

FROM [DB].[dbo].[DB_View]
WHERE UserID = '9999'

用户的结果集约为600行，视图通常有大约6,000-15,000行。我最初的想法是获取我的用户结果集，然后将每个用户存储到参数，然后将其传递到我硬编码用户ID的查询中。可悲的是，我甚至无法弄清楚这样做的SQL。（我猜你有更好的方法可以做到这一点，如果你知道你的SQL ....）我已经看到了使用游标和东西的东西，但我真的不太了解它。

有什么想法吗？

Answer 1

如果我理解你的话：

SELECT [UserID],
    COUNT(CASE WHEN Age < 14 THEN 1 ELSE NULL END) AS [Less Than 14 Days],
    COUNT(CASE WHEN Age BETWEEN 14 AND 17 THEN 1 ELSE NULL END) AS [14 to 17 Days],
    COUNT(CASE WHEN Age BETWEEN 18 AND 28 THEN 1 ELSE NULL END) AS [18 to 28 Days],
    COUNT(CASE WHEN Age BETWEEN 29 AND 44 THEN 1 ELSE NULL END) AS [29 to 44 Days],
    COUNT(CASE WHEN Age >= 45 THEN 1 ELSE NULL END) AS [Over 45 Days]

FROM [DB].[dbo].[DB_View]
GROUP BY [UserID]

Answer 2

您可以使用一个简单的组来执行此操作，使用CASE语句按年龄条件求和：

SELECT [UserID],
       SUM(case when Age < 14 then 1 else 0 end) AS "Less Than 14 Days",
       SUM(case when Age BETWEEN 14 AND 17 then 1 else 0 end) as "14 to 17 Days",
       SUM(case when Age BETWEEN 18 AND 28 then 1 else 0 end) as "18 to 28 Days",
       SUM(case when Age BETWEEN 29 AND 44 then 1 else 0 end) as "29 AND 44 Days",
       SUM(case when Age BETWEEN 29 AND 44 then 1 else 0 end) as "29 AND 44 Days",
       SUM(case when Age >= 45 then 1 else 0 end) as "Over 45 Days"
from [DB].[dbo].[DB_View] 
where  UserID = '9999'
group by userID

T-SQL：从结果集构建新表

2 个答案: