如何使用 php 将 mysql 查询加载到 chartjs？答案

【问题标题】：how to load mysql query to chartjs with php?如何使用 php 将 mysql 查询加载到 chartjs？
【发布时间】：2019-07-23 08:38:27
【问题描述】：

我需要帮助，你们能帮帮我吗？这是我的问题。我有 2 个文件是：

main.js
index.php

这是main.js的来源：

var ctx = document.getElementById("percent-chart2").getContext("2d");
if (ctx) {
  ctx.height = 209;
  var myChart = new Chart(ctx, {
    type: 'doughnut',
    data: {
      datasets: [
        {
          label: "My First dataset",
          data: [<?php while ($p = mysqli_fetch_array($jumlah)) { echo '"' . $p['jumlah'] . '",';}?>],
          backgroundColor: [
            '#fa4251',
            '#00b5e9'
          ],
          hoverBackgroundColor: [
            '#fa4251',
            '#00b5e9'
          ],
          borderWidth: [
            0, 0
          ],
          hoverBorderColor: [
            'transparent',
            'transparent'
          ]
        }
      ],
      labels:
      [
       <?php while ($p = mysqli_fetch_array($severity)) { echo '"' . $p['severity'] . '",';}?>
      ]
    }

这是index.php：

<?php
$koneksi = mysqli_connect("localhost", "root", "waf", "waf");
$severity = mysqli_query($koneksi, "SELECT severity FROM severity order by severity asc");
$jumlah = mysqli_query($koneksi, "SELECT jumlah FROM severity order by severity asc");
?>

如果我从 mysql 运行查询，我得到的输出：

mysql> SELECT severity FROM severity order by severity asc;
+----------+
| severity |
+----------+
| CRITICAL |
| WARNING  |
+----------+
2 rows in set (0.00 sec)

和，

mysql> SELECT jumlah FROM severity order by severity asc;
+--------+
| jumlah |
+--------+
|     35 |
|     35 |
+--------+
2 rows in set (0.00 sec)

当我运行 php 时，什么都没有发生或出现，只是空白页。我该怎么办？ (-_-")

另一个问题，我可以从 js 运行查询 mysql 吗？

谢谢..

【问题讨论】：

data: [<?php while ($p = mysqli_fetch_array($jumlah)) { echo '"' . $p['jumlah'] . '",';}?>]这个PHP代码不会生成一个有效的数组
stackoverflow.com/questions/1475297/phps-white-screen-of-death 的可能重复项（“只是空白页”）

标签： javascript php mysql mysqli chart.js

【解决方案1】：

最好先在 index.php 中的 javascript 数组中设置 $p 数组的值，然后在 main.js 中使用它。例如：

<script>
    var fields= [<?php  while ($p = mysqli_fetch_array($jumlah)) { echo '"' . $p['jumlah'] . '",';} ?>];
</script>
<?php
$koneksi = mysqli_connect("localhost", "root", "waf", "waf");
$severity = mysqli_query($koneksi, "SELECT severity FROM severity order by severity asc");
$jumlah = mysqli_query($koneksi, "SELECT jumlah FROM severity order by severity asc");
?>

main.js

var ctx = document.getElementById("percent-chart2").getContext("2d");
if (ctx) {
  ctx.height = 209;
  var myChart = new Chart(ctx, {
    type: 'doughnut',
    data: {
      datasets: [
        {
          label: "My First dataset",
          data: fields,
          backgroundColor: [
            '#fa4251',
            '#00b5e9'
          ],
          hoverBackgroundColor: [
            '#fa4251',
            '#00b5e9'
          ],
          borderWidth: [
            0, 0
          ],
          hoverBorderColor: [
            'transparent',
            'transparent'
          ]
        }
      ],
      labels:
      [
       <?php while ($p = mysqli_fetch_array($severity)) { echo '"' . $p['severity'] . '",';}?>
      ]
    }

注意：main.js 文件必须在 indx.php 之后调用

【讨论】：