Query 2 COUNTS 用 GROUP BY 语句出问题

Question

我正在尝试查询 table 中每个组的注册用户和注册用户的计数。

但是，我不断收到重复的群组名称、注册和登记。我需要它只是唯一的组名，在其各自的列中有计数。我是新手，我已经为此纠结了 3 天。任何帮助将不胜感激。下面是我最接近的，但仍然得到重复的组名。

WITH CTE_GROUP as (
    SELECT DISTINCT [GROUP] AS GROUPS
    FROM TABLE1
    WHERE AUTH_PAGE = 'X' AND CAST(CreationDate AS DATE) >= '2022-04-01' AND CAST(CreationDate AS DATE) < '2022-05-01' AND EMAIL IS NOT NULL AND EMAIL <> '' AND EMAIL NOT LIKE '%@company.com' OR CAST(CreationDate AS DATE) >= '2022-04-01' AND CAST(CreationDate AS DATE) < '2022-05-01' AND EMAIL IS NOT NULL AND EMAIL <> '' AND EMAIL NOT LIKE '%@company.com'
    GROUP BY [GROUP]
),
CTE_REGISTERED as (
    SELECT [GROUP], COUNT (*) AS REGISTERED
    FROM TABLE1
    WHERE CAST(CreationDate AS DATE) >= '2022-04-01' AND CAST(CreationDate AS DATE) < '2022-05-01' AND EMAIL IS NOT NULL AND EMAIL <> '' AND EMAIL NOT LIKE '%@company.com'
    GROUP BY [GROUP]
),
CTE_ENROLLED as (
    SELECT [GROUP], COUNT (*) AS ENROLLED
    FROM TABLE1
    WHERE AUTH_PAGE = 'X' AND CAST(CreationDate AS DATE) >= '2022-04-01' AND CAST(CreationDate AS DATE) < '2022-05-01' AND EMAIL IS NOT NULL AND EMAIL <> '' AND EMAIL NOT LIKE '%@company.com'
    GROUP BY [GROUP]
)
SELECT DISTINCT GROUPS, REGISTERED, ENROLLED
FROM CTE_GROUP, CTE_REGISTERED, CTE_ENROLLED

我的结果是这样的

GROUPS               REGISTERED       ENROLLED
CompanyA              3                 2
CompanyB              3                 3
CompanyA              3                 2
CompanyB              3                 3

我要找的结果应该是

GROUPS               REGISTERED       ENROLLED
CompanyA              3                 2
CompanyB              3                 3

谢谢

Answer 1

您的结果集基本上是一个 CROSS JOIN，因为您在三个 CTE 之间没有 JOIN 条件。

试试这个：

SELECT 
    * 
FROM 
    CTE_GROUP AS [Groups] 
    INNER JOIN CTE_Registered AS [Registered] ON [Groups].[GROUPS] = [Registered].[GROUP]
    INNER JOIN CTE_ENROLLED AS [Enrolled] ON [Groups].[GROUPS] = [Enrolled].[GROUP]

一般来说，当你处理来自多个表的数据时（无论它们是实际的物理表、视图，还是in-memory表），你需要让数据库引擎知道这些数据是如何相关的.为此，您可以创建关系（使用主键和外键），并使用 JOIN 条件在查询中指示引擎。表可以通过多个字段关联，在这种情况下，您可以在 JOIN 条件中将它们串在一起，就像 WHERE 子句一样。

请注意，有多种方法可以执行 JOIN，结果将取决于您是否使用了正确的类型。在我提供的示例查询中，我使用了 INNER JOIN，它确保您只返回包含在 JOIN.

中的两个表中都存在的结果

Answer 2

我相信您需要在单个查询中使用“条件聚合”：

SELECT
      [group]
    , count(*) AS registered
    , count(CASE WHEN AUTH_PAGE = 'X' THEN 1 END) AS enrolled
FROM table1
WHERE CreationDate >= '20220401'
    AND CreationDate < '20220501'
    AND EMAIL NOT LIKE '%@company.com'
GROUP BY
     [group]
;

本质上，您在聚合函数中使用 case expression，例如 count()，这样您的计数将继承通过 case expression 定义的“条件”。

另请注意，您无需将 [CreationDate] 强制转换为“日期”即可使 where 子句谓词起作用。所有 date/time 相关的数据类型都可以与日期文字进行比较。此外，在 SQL 服务器中，“最安全”的日期文字只是 YYYYMMDD 格式。

Query 2 COUNTS 用 GROUP BY 语句出问题

Query 2 COUNTS with a GROUP BY statement trouble

sql

sql-server