MySQL 在 Between 语句中使用 max(date)

Question

感谢任何帮助。我试图在 CASE 语句中使用 max(date) 但语法不正确或者 ??

// This works    
SELECT
     ROUND(sum(CASE WHEN Document_Date BETWEEN  DATE_FORMAT("2019-01-01", "%Y-%m-%d") AND  DATE_FORMAT("2019-01-31", "%Y-%m-%d") THEN GTotal END),0) TOTAL2019
FROM
salesdata

// But I want to use max(Document_Date) which is 2019-01-31 like so and have tried cast and different combos, but it comes out null or says invalid use of group function.  Document_Date is datetime in DB

    SELECT
         ROUND(sum(CASE WHEN Document_Date BETWEEN  DATE_FORMAT("2019-01-01", "%Y-%m-%d") AND  DATE_FORMAT(max(Document_Date), "%Y-%m-%d") THEN GTotal END),0) TOTAL2019
    FROM
    salesdata

我做错了什么 - 感谢您的帮助。

Answer 1

您正在尝试将 max 聚合与 sum 结合使用。一般来说，如果不使用子查询就无法做到这一点。

检查我的替代解决方案

SELECT
     ROUND(sum(
       CASE WHEN Document_Date BETWEEN  DATE_FORMAT("2019-01-01", "%Y-%m-%d") AND  (select max(Document_date) from salesData) THEN 
         GTotal 
       END),
     0) TOTAL2019
FROM
salesdata