我正在尝试为图书馆预订系统创建一些统计数据。我的 sql 查询结果如下所示。
total_no_students| department | property | month 241 | Physics | undergraduate | Nov 236 | Physics | undergraduate | Dec 254 | Physics | postgraduate | Nov 210 | Physics | postgraduate | Dec 193 | Architecture| undergraduate | Nov 181 | Architecture| undergraduate | Dec 127 | Architecture| postgraduate | Nov 292 | Architecture| postgraduate | Dec 134 | Biology | undergraduate | Nov 188 | Biology | undergraduate | Dec 129 | Biology | postgraduate | Nov 219 | Biology | postgraduate | Dec
我正在尝试使用 php 编写一些代码来创建具有以下外观的统计表:
|Physics-undergrad|Physics-postgrad|Architecture-undergrad|Architecture-postgrad| Nov | 241 | 254 | 193 | 127 | Dec | 236 | 210 | 181 | 292 |
我必须使用数组和一些循环(foreach)通过 php(枢轴技术)对其进行转换。我尝试这样做，但我对嵌套循环感到困惑。
我编写的代码如下:
$csvArray = array();
$departments = array('Physics','Architecture','Biology');
$properties = array('undergraduate','postgraduate');
$con = mysqli_connect($mysql_hostname, $mysql_user, $mysql_password, $mysql_dbname);
$sql="SELECT count(id) as total_no_students, department, property, MONTH(table1.created) as month
FROM table1
left JOIN table2
ON table2.barcode=table1.input
group by department, property, month";
$res=mysqli_query($con,$sql);
while($row=mysqli_fetch_array($res)){
$time = $row['month'];
if (!array_key_exists($time, $csvArray) ) {
foreach ($departments as $department) {
$csvArray[$department] = array();
foreach($properties as $property) {
$csvArray[$department][$property] = array();
}
}
}
$department = $row['department'];
$property = $row['property'];
$total_no_students = $row['total_no_students'];
$csvArray[$time][$departments][$property] = $total_no_students;
}
有什么帮助如何将使用 php 的查询转换为上表吗？
最佳答案
select "month",
SUM(case when department = 'Physics' and property = 'undergraduate' then total_no_students else 0 end) as "Physics-undergrad",
[...]
from table_name
group by "month"
关于php - 如何使用php数组将sql查询结果转换为数据透视表？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/27687160/