平日最近 3 天记录

Question

我有一个问题。在过去 3 天（工作日）中，我想列出没有数据的那些。

服务表：records1：

---------------------    ---------------------------------------    
|   id   |   name   |    |   id   |    service_id |     date   |
|-------------------|    |-------------------------------------|
|   1    |   a      |    |   1    |        1      | 2019-03-26 |  
|   2    |   ab     |    |   2    |        3      | 2019-03-25 |
|   3    |   ac     |    |   3    |        6      | 2019-03-24 | (weekend)          
|   4    |   ad     |    |   4    |        4      | 2019-03-26 |
|   5    |   af     |    ---------------------------------------
|   6    |   ah     |
---------------------


Select s.id, s.name from service s 
where s.id not in (select service_id from records1 where date(dateff) >     DATE_SUB(CURDATE(), INTERVAL 3 DAY) and WEEKDAY(curdate()) in (0,1,2,3,4) )
and WEEKDAY(curdate()) in (0,1,2,3,4)

我需要：例如今天是星期二（2019-03-26）。如果最近 3 天（星期二、星期一、星期五）在表格中没有数据，它将列出名称。

表：

---------------------     
|   name |   name   |    
|-------------------|  
|   1    |   a      |   
|   3    |   ac     |              
|   4    |   ad     | 
---------------------

Answer 1

https://www.db-fiddle.com/f/bwobAMFSchEDq6AxbHaL7/0

SELECT 
    s.id,
    s.name,                   
    COUNT(DISTINCT r.id)
FROM service s
LEFT JOIN records1 r
ON date(r.dateff) >= @today - INTERVAL @period DAY
   AND r.service_id = s.id
   AND WEEKDAY(r.dateff) in (0,1,2,3,4)
CROSS JOIN (
  SELECT 
      @today := DATE('2019-03-26'), 
      @weekDay := WEEKDAY(@today), 
      @period := IF(@weekDay IN (2,3,4),3, IF(@weekDay IN (0,1,6), 5, 4))
) vars
GROUP BY s.id, s.name
HAVING COUNT(DISTINCT r.id) = 0