如何在javascript中使用php變量

Question

我意識到您不能在腳本中使用 php，但我正在努力用 SQL 數據填充圖表。 這是代碼的簡化版本。 我已經閱讀了這里的其他確切問題，但根本無法解決這個問題..希望有人能提供幫助，謝謝

<?php
    $query = mysql_query("SELECT count(green), count(amber), count(red) FROM cards");
    $myData = mysql_fetch_assoc($query);
    $green = $myData['count(green)'];
    $amber = $myData['count(amber)'];
    $red = $myData['count(red)'];
?>  
<div id="students" style="height: 250px;">
<script type="text/javascript">
    Morris.Donut({
      element: 'students',
      data: [
        {value: '<?php $green; ?>', label: 'Green'},
        {value: '<?php $amber; ?>', label: 'Amber'},
        {value: '<?php $red; ?>', label: 'Red'},
      ],
      formatter: function (x) { return x }
    }).on('click', function(i, row){
      console.log(i, row);
    });
</script>
</div>

Answer 1

1. 建議使用mysql別名返回可讀鍵：

$query = mysql_query("SELECT count(green) as `cgreen`, count(amber) as `camber`, count(red) as `cred` FROM cards");

2. 建議對列名、表名和數據庫名進行轉義：

$query = mysql_query("SELECT count(`green`) as `cgreen`, count(`amber`) as `camber`, count(`red`) as `cred` FROM `cards`");

3. 如果您使用 utf-8 作為文件編碼，那么在 php 中創建 JSON 並將其傳遞給 JS 非常容易：

$json = json_encode($myData);

var tmpd = JSON.parse('<?=$json; ?>');
Morris.Donut({
  element: 'students',
  data: [
    {value: tmpd.cgreen, label: 'Green'},
    {value: tmpd.camber, label: 'Amber'},
    {value: tmpd.cred, label: 'Red'},
  ],
  formatter: function (x) { return x }
}).on('click', function(i, row){
  console.log(i, row);
});