Question

我已经查询了本周检索每日数据的信息。我希望得到如下表格：

  hari   total  finish   issue  
 ------  ------  ------  --------
 1       0       0         0
 2       0       0         0
 3       1       0         1
 4       1       1         0
 5       0       0         0
 6       0       0         0
 7       0       0         0

这是我的疑问：

SELECT  DAYOFWEEK(`waktu`) AS hari,
COALESCE( (COUNT(*) ), 0) AS total, 
COUNT(IF(`jarak`<70,1,NULL)) AS finish, 
COUNT(IF(`jarak`>70,1,NULL)) AS issue 
FROM `presensi` 
WHERE WEEKOFYEAR(`waktu`)=WEEKOFYEAR(NOW())
GROUP BY hari;

但是，查询不显示零结果。如何用emty数据显示一周中的所有日子，包括白天？

Answer 1

一周只有7天，所以这对left join很容易：

SELECT dow.dow  AS hari,
       COUNT(p.waktu)  AS total, 
       SUM(`jarak` < 70) AS finish, 
       SUM(jarak > 70) AS issue 
FROM (select 0 as dow union all select 1 union all select 2 union all select 3 union all
      select 4 union all select 5 union all select 6
     ) dow left join
     `presensi` p
     on p.DAYOFWEEK(`waktu`) = dow.dow and
        WEEKOFYEAR(`waktu`) = WEEKOFYEAR(NOW())
GROUP BY dow.dow;

Answer 2

我已经解决了我的问题。我创建了一个带有日期列表的虚拟表（来自@ drew-pierce的想法）。我的查询：

SELECT 
  h.`id`, 
  COALESCE(d.total,0) AS total, 
  COALESCE(d.finish,0) AS finish,  
  COALESCE(d.issue,0) AS issue
FROM
  hari_dummy h 
LEFT JOIN 
(
  SELECT 
    DAYOFWEEK(p.waktu) AS hari,
    COUNT(p.waktu) AS total,
    COUNT(IF(p.`jarak` < 70, 1, NULL)) AS finish,
    COUNT(IF(p.`jarak` > 70, 1, NULL)) AS issue 
  FROM
    `presensi` p 
  WHERE 
     WEEKOFYEAR(waktu) = WEEKOFYEAR(NOW()) 
  GROUP BY hari
 ) d 
ON d.hari = h.`id` 
ORDER BY h.id ASC;

MySQL计数行与dayofweek包括零结果

2 个答案: