PHP：字符串不等于字符串

Question

项目：

我正在解析一个 CSV 文件并将其数据插入到数据库中。在一个循环中，我获取 CSV 值并验证它们（确保它们已被填充），这些值的存储方式如下：

$current_order_number = $array[$i]['order_number'] ?? null;

("order_number" 是 CSV 文件中标题的名称。)

问题：

当我手动输入“order_number”时，$current_order_number 为空。

当我从 CSV 文件中复制“order_number”时，$current_order_number 是正确的。

（这是唯一可以执行此操作的 CSV 标头。我手动输入了其余部分，它们运行良好。）

调试：

我使用了一个字符串到ASCII的转换器，发现正确的字符串（“order_number”）转换成：

NULL 111 114 100 101 114 95 110 117 109 98 101 114

同时将不正确的字符串（“order_number”）转换成

111 114 100 101 114 95 110 117 109 98 101 114

我试过（删除空值）：

$value = str_replace("\0", "", $value);

而且（认为是编码）：

$value = utf8_encode($value);

没有运气。

完整代码：

$target_path = $target_path . basename( $_FILES['csv_raw']['name'] );

if ( move_uploaded_file($_FILES['csv_raw']['tmp_name'], $target_path) ) {
  echo "File Upload Successful: -- [" . $target_path . "] --\r\n";
  $array = $fields = array();
  $i = 0;
  $handle = @fopen($target_path, "r");
  if ($handle) {
    while (($row = fgetcsv($handle, 4096)) !== false) {
      if (empty($fields)) {
        $fields = $row;
        continue;
      }
      foreach ($row as $k=>$value) {
        if (strlen(trim($value)) == 0) {
          $value = 0;
        }
        $value = str_replace("\0", "", $value);
        $array[$i][$fields[$k]] = $value;
      }
      //print_r($array[$i]);
      //"order_number"(correct [NULL 111 114 100 101 114 95 110 117 109 98 101 114])
      //"order_number" (incorrect [111 114 100 101 114 95 110 117 109 98 101 114])
      $current_order_number = $array[$i]['order_number'] ?? null;
      $current_order_line = $array[$i]['order_line'] ?? null;
      $current_shipment_number = $array[$i]['shipment_number'] ?? null;
      $current_package_number = $array[$i]['package_number'] ?? null;
      $current_package_item_number = $array[$i]['package_item_num'] ?? null;
      $current_item_code = $array[$i]['item_code'] ?? null;
      $current_quantity = $array[$i]['qty_shipped'] ?? null;
      $query = query("SELECT * FROM `osl` WHERE `order_number` = ".$current_order_number." AND `item_code` = ".$current_item_code." ");
      confirm($query);

      if (mysqli_num_rows($query) == 0) {
        $query = query("SELECT * FROM `osl_daily` WHERE `order_number` = ".$current_order_number." AND `item_code` = ".$current_item_code." ");
        confirm($query);
        if (mysqli_num_rows($query) == 0) {
          $query = query("
          INSERT INTO `osl_daily` (`local_id`, `order_number`, `order_line`, `shipment_number`, `package_number`, `package_item_number`,`item_code`, `quantity`)
          VALUES (NULL,".$current_order_number.",".$current_order_line.",".$current_shipment_number.",".$current_package_number.",".$current_package_item_number.",".$current_item_code.",".$current_quantity.")
          ");
          confirm($query);
          echo "Success: Order Number ".$current_order_number." Lines Have Been Imported Successfully.\r\n";
        }
        else {
          echo "Error: Order Number ".$current_order_number." Line Already Exists in osl_daily.\r\n";
        }
      }
      else {
        echo "Error: Order Number ".$current_order_number." Line Already Exists in osl.\r\n";
      }

      $i++;
    }
    if (!feof($handle)) {
      echo "Error: unexpected fgets() fail\r\n";
    }
    fclose($handle);
  }
}
else {
  echo "Error: File Upload Failed\r\n";
}

CSV 代码： order_number,order_line,shipment_number,package_number,package_item_num,item_code,qty_shipped 43441,1,37294,1,1,10000,1 43441,2,37294,1,2,10010,1

为什么“order_number”不等于“order_number”？以及如何使 order_number = order_number？

Answer 1

前三个字符似乎是问题所在。文件开头有字符 239、187 和 191。看看这种代码组合似乎会为 UTF-8 提供 byte order mark (BOM)。

处理此问题的简单方法是将它们从第一个字段中删除（如果存在）...

if (empty($fields)) {
    if ( substr($row[0],0,3) === chr(239).chr(187).chr(191))    {
        $row[0] = substr($row[0], 3);
    }
    $fields = $row;
    continue;
}