sql-server - 在 SQL Server 中按多个格式化和强制转换的列分组

Question

我在 SQL Server 中对多个列进行分组时遇到了麻烦。我知道 Group by 序数不起作用，而且我不能在 Group by 中使用别名。列出列很痛苦，特别是如果我在 SELECT 语句中格式化和转换了列。

例如

SELECT 
CONCAT('ABC',column1) AS col1,
cast('XYZ AS VARCHAR) AS col2, 
column3 AS col3, 
cast(ISNULL(column4,0) AS MONEY) / 100 AS col4, 
....
....
count(DISTINCT table2.ID) AS col15
GROUP BY <>

以上是我使用的示例查询，当我从不同的表中选择不同的列加入它们时，它很复杂。解决方案是什么？

Answer 1

如果你真的想达到这个结果，唯一的机制是使用子查询或 CTE：

子查询：

SELECT *
FROM   (
        SELECT
            CONCAT('ABC',column1) AS col1,
            cast('XYZ AS VARCHAR) AS col2, 
            column3 AS col3, 
            cast(ISNULL(column4,0) AS MONEY) / 100 AS col4, 
            ....
            ....
            count(DISTINCT table2.ID) AS col15
        )
GROUP BY <>

公用表表达式 (CTE)：

;WITH data AS (
    SELECT
            CONCAT('ABC',column1) AS col1,
            cast('XYZ AS VARCHAR) AS col2, 
            column3 AS col3, 
            cast(ISNULL(column4,0) AS MONEY) / 100 AS col4, 
            ....
            ....
            count(DISTINCT table2.ID) AS col15
    )
SELECT *
FROM Data
GROUP BY <>