计算比例（百分比）

Question

您能帮我计算

的比例吗

Table
user_id    attendance   Date
1            1           01.01.2018
2            Null        01.01.2018
3            1           02.01.2018
4            Null        03.01.2018
5            1           03.01.2018

如果用户出席，则为1，否则为-空。

需要计算01.01.18-02.01.18期间的出勤百分比。 例如，在2018年1月1日，两个用户中有1个用户（50％），在02.01.2018-100％。

谢谢！

Answer 1

您可以尝试以下查询：

<div id="slider">
<figure>
<div class="page">
<div class="project">
  <div class="col project-img">
    <img src="https://via.placeholder.com/350x350">
  </div>
  <div class="col project-info">info 1</div>
</div>
</div>
<div class="page">
<div class="project">
  <div class="col project-img">
    <img src="https://via.placeholder.com/350x350">
  </div>
  <div class="col project-info">info 2</div>
</div>
</div>
<div class="page">
<div class="project">
  <div class="col project-img">
    <img src="https://via.placeholder.com/350x350">
  </div>
  <div class="col project-info">info 3</div>
</div>
</div>
<div class="page">
<div class="project">
  <div class="col project-img">
    <img src="https://via.placeholder.com/350x350">
  </div>
  <div class="col project-info">info 4</div>
</div>
</div>
<div class="page">
<div class="project">
  <div class="col project-img">
    <img src="https://via.placeholder.com/350x350">
  </div>
  <div class="col project-info">info 5</div>
</div>
</div>
</figure>
</div>

@keyframes slidy {
0% { left: 0%; }
20% { left: 0%; }
25% { left: -100%; }
45% { left: -100%; }
50% { left: -200%; }
70% { left: -200%; }
75% { left: -300%; }
95% { left: -300%; }
100% { left: -400%; }
}

body { margin: 0; } 

div#slider { overflow: hidden; }

div#slider figure .page { width: 100vw; float: left; }

div#slider figure { 
position: relative;
width: 500vw;
margin: 0;
left: 0;
text-align: left;
font-size: 10;
animation: 30s slidy infinite; 
}

.page {
display: flex; 
justify-content: center; 
}

.project {
display: flex; 
align-items: center; 
}

这假定给定用户在给定日期最多只能出现一次出席。它还假定您的SELECT Date, 100.0 * COUNT(attendance) / COUNT(*) AS perc_attendance FROM yourTable WHERE Date BETWEEN '2018-01-01' AND '2018-01-02' GROUP BY Date; 列是实际的日期列，而不仅仅是文本。

Demo

Answer 2

select v.date1 , case when s.no_people is null and v.showup_people then 100
when v.showup_people is null and s.no_people is not null then 0
else (v.showup_people / (v.showup_people + s.no_people))*100  end outcome 

from
(select count(*) as no_people , date as date1
   from yourTable
   where attendance is null
   group by date) s
   right outer join
   (select count(*) as showup_people , date as date1
   from yourTable
   where attendance is not null
   group by date) v
on(v.date1 = s.date1)

将“ from”表替换为您的表名。

这将始终有效，无论您有多少个约会。 情况是因为null + mysql中的数字为null。 在oracle sql中，您可以只使用最后一个else语句。

这是一个Demo

Answer 3

如果要显示为新表，则可以使用此查询，但必须先创建一个：

SELECT Date,100.0 * COUNT(attendance) / COUNT(*) AS attendancepercent
FROM Table WHERE Date BETWEEN '2018-01-01' AND '2018-01-02'
GROUP BY Date;