如何从PHP [开放alpr的JSON结果]读取这种类型的Json文件？

Question

我需要知道如何提取JSON数据，比如下面发布到php的JSON格式，我试图使用php脚本将Json文件键值数据提取到mysql中。下面的JSON来自openalpr，在命令行上使用alpr作为json导出

  "version": 2,
  "data_type": "alpr_results",
  "epoch_time": 1594858871000,
  "img_width": 3232,
  "img_height": 3232,
  "processing_time_ms": 522.5,
  "regions_of_interest": [],
  "results": [
    {
      "plate": "QAA1989C",
      "confidence": 90.09095,
      "matches_template": 0,
      "plate_index": 0,
      "region": "my",
      "region_confidence": 0,
      "processing_time_ms": 42.125999,
      "requested_topn": 10,
      "coordinates": [
        {
          "x": 1149,
          "y": 2071
        },
        {
          "x": 1836,
          "y": 2071
        },
        {
          "x": 1836,
          "y": 2268
        },
        {
          "x": 1149,
          "y": 2268
        }
      ]
    }
  ]
}

我一直得到的只是类似于这个Illegal string offset 'result 的错误，这是我测试过的显示板块号的php代码：能帮助我如何使用脚本获取json数组中的子数组的值吗？谢谢**

我使用了以下代码，不确定有关子元素的键值的错误是什么

$filename = "results.json";
          $data = file_get_contents($filename); //Read the JSON file in PHP
          $array = json_decode($data, true); //Convert JSON String into PHP Array
          
          foreach ($data['results']['results'] AS $d)
          {
            echo $d['plate'];
            }

Answer 1

您的json字符串错了，第一行缺少{

$json = '
{
    "version": 2,
    "data_type": "alpr_results",
    "epoch_time": 1594858871000,
    "img_width": 3232,
    "img_height": 3232,
    "processing_time_ms": 522.5,
    "regions_of_interest": [],
    "results": [
        {
            "plate": "QAA1989C",
            "confidence": 90.09095,
            "matches_template": 0,
            "plate_index": 0,
            "region": "my",
            "region_confidence": 0,
            "processing_time_ms": 42.125999,
            "requested_topn": 10,
            "coordinates": [
                {
                    "x": 1149,
                    "y": 2071
                },
                {
                    "x": 1836,
                    "y": 2071
                },
                {
                    "x": 1836,
                    "y": 2268
                },
                {
                    "x": 1149,
                    "y": 2268
                }
            ]
        }
    ]
}
';

$data = json_decode($json,true);

foreach ($data['results'] AS $d) {
    echo $d['plate'];
}