用于将MySQL查询转换为CSV的PHP代码

<?php
// 连接到MySQL数据库
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDB";

$conn = new mysqli($servername, $username, $password, $dbname);

// 检查连接
if ($conn->connect_error) {
  die("连接失败: " . $conn->connect_error);
}

// 查询数据
$sql = "SELECT * FROM myTable";
$result = $conn->query($sql);

// 创建CSV文件
$csv_filename = "output.csv";
$csv_file = fopen($csv_filename, "w");

// 将查询结果写入CSV文件
if ($result->num_rows > 0) {
  // 获取字段名
  $row = $result->fetch_assoc();
  $field_names = array_keys($row);
  fputcsv($csv_file, $field_names);

  // 获取数据行
  while ($row = $result->fetch_assoc()) {
    fputcsv($csv_file, $row);
  }
}

// 关闭文件和数据库连接
fclose($csv_file);
$conn->close();
?>