MariaDB 查询 SUM() OVER (PARTITION BY)

Posted 2023-05-08

【中文标题】MariaDB 查询 SUM() OVER (PARTITION BY)

【英文标题】：MariaDB Query SUM() OVER (PARTITION BY)

【发布时间】：2021-12-29 14:34:49

【问题描述】：

我创建了一个查询，它根据某些条件（日期、isSpecial、isFirst、小时）对行进行不同的计数。 这是查询：

WITH test AS 
(
    SELECT customer_id, performance.id, performance_id, 
           Name, Date as zDate, Date, isSpecial, isFirst, hour 
    FROM recording 
    INNER JOIN performance ON performance_id = performance.id
)

SELECT id, Date, Name, isSpecial, isFirst, hour,
    IF(NOT isSpecial AND NOT isFirst AND hour,
        (SELECT SUM(CASE WHEN NOT isFirst AND NOT isSpecial
                AND hour AND Date <= zDate
              THEN 1 ELSE 0 END) 
         FROM recording 
         INNER JOIN performance ON recording.performance_id = performance.id 
         WHERE customer_id = 1
        ), 
        IF(isSpecial AND NOT isFirst AND hour,  
            (SELECT CONCAT('P',SUM(CASE WHEN NOT isFirst
                    AND isSpecial AND hour AND Date <= zDate
                  THEN 1 ELSE 0 END)) 
             FROM recording 
             INNER JOIN performance ON recording.performance_id = performance.id 
             WHERE customer_id=1
            ),  
            IF(isFirst,'First','-')
        )
    ) AS myTest 
FROM test 
WHERE customer_id = 1 
ORDER BY Date

结果：

查询为我提供了一个 customer_id 的所需结果，而无需我设置变量。

我现在已经用 SUM() OVER (PARTITION BY customer_id) 试验了很长时间，但这总是导致“子查询返回多个记录”。

...
(SELECT CONCAT('P', SUM(CASE WHEN NOT isErst AND isProbatorik
                        AND therapiestunde AND Datum <= zDatum 
                     THEN 1 ELSE 0 END)
            OVER (PARTITION BY customer_id))
 FROM leistungserfassung 
 INNER JOIN leistung ON leistungserfassung.Leistung_id = leistung.id),
...

是否可以将此总和扩展到所有 customer_id，以便对于每个 customer_id 总是再次汇总？

【问题讨论】：

不要为此使用相关子查询。只需在外部选择列表中使用 SUM(...) OVER (PARTITION BY customer_id ....) AS xxx 。很可能，您甚至都不需要 CTE 术语。

没有CREATE TABLE 语句很难测试。您的 SQL 不限定 每个 列引用，因此我们不知道哪个表包含每一列。

SUM(CASE WHEN boolean_expression THEN 1 ELSE 0 END) 可以简写为SUM(boolean_expression)

请显示想要的结果。

【参考方案1】：

这只是猜测，没有关于您的架构/表的足够详细信息：

试试这个（使用 mysql 8.0、MariaDB 10.6、10.5、10.4 等）：

注意：如果您想要一个正在运行的 SUM，只需在窗口规范中添加一个 ORDER BY Date 子句（或类似的东西）。根据您的实际要求，可以删除显式日期逻辑。没有一点数据和预期的结果，很难判断。

The fiddle

WITH test AS (
        SELECT customer_id, performance.id, performance_id
             , Name, Date as zDate, Date, isSpecial, isFirst, hour
          FROM recording
          JOIN performance
            ON performance_id = performance.id
     )
SELECT id, Date, Name, isSpecial, isFirst, hour
     , CASE WHEN NOT isSpecial AND NOT isFirst AND hour
            THEN SUM(CASE WHEN NOT isFirst AND NOT isSpecial AND hour AND Date <= zDate THEN 1 ELSE 0 END) OVER w
            WHEN isSpecial AND NOT isFirst AND hour
            THEN CONCAT('P', SUM(CASE WHEN NOT isFirst AND isSpecial AND hour AND Date <= zDate THEN 1 ELSE 0 END) OVER w)
            WHEN isFirst
            THEN 'First'
            ELSE '-'
        END AS myTest
  FROM test
WINDOW w AS (PARTITION BY customer_id)
 ORDER BY customer_id, Date
;

将运行SUM（Date）行为添加到窗口函数并删除显式Date <= zDate逻辑：

WITH test AS (
        SELECT customer_id, performance.id, performance_id
             , Name, Date, isSpecial, isFirst, hour
          FROM recording
          JOIN performance
            ON performance_id = performance.id
     )
SELECT id, Date, Name, isSpecial, isFirst, hour
     , CASE WHEN NOT isSpecial AND NOT isFirst AND hour
            THEN SUM(CASE WHEN NOT isFirst AND NOT isSpecial AND hour THEN 1 ELSE 0 END) OVER w
            WHEN isSpecial AND NOT isFirst AND hour
            THEN CONCAT('P', SUM(CASE WHEN NOT isFirst AND isSpecial AND hour THEN 1 ELSE 0 END) OVER w)
            WHEN isFirst
            THEN 'First'
            ELSE '-'
        END AS myTest
  FROM test
WINDOW w AS (PARTITION BY customer_id ORDER BY Date)
 ORDER BY customer_id, Date
;

结果（没有数据）：

id	Date	Name	isSpecial	isFirst	hour	myTest

设置（我确定这些表格不正确。问题未包含此详细信息）：

CREATE TABLE recording   ( id int, performance_id int, customer_id int );

CREATE TABLE performance (
   id int, Name VARCHAR(20), Date date
 , isSpecial int, isFirst int, hour int
);

【讨论】：

非常感谢！这对我来说非常有用！新年快乐！