使用 PHP 将 mysql 值转储到 JSON 文件中

我正在尝试使用 PHP 从 mysql 数据库生成 JSON 文件。到目前为止，我有：

<?php

error_reporting(-1);

$result=mysql_query("SELECT * FROM wp_posts");

$i=0;
while($row=mysql_fetch_array($result)) { 
$response[$i]['post_status']  = $row['post_status']; 
$response[$i]['post_title']= $row['post_title'];
$data['posts'][$i] = $response[$i];
$i=$i+1;
} 

$json_string = json_encode($data);

$file = 'file.json';
file_put_contents($file, $json_string);
?> 

这将创建 file.json 文件，但该文件仅包含“null”。

随机猜测：json_encode需要 UTF-8 编码数据，并将在任何非 UTF-8、非 ASCII 输入上表现出您所描述的行为。您从数据库获取的数据可能是 Latin-1 编码的。

Either set your database connection to utf8 to receive UTF-8 encoded data directly from the database (see UTF-8 all the way through https://stackoverflow.com/q/279170/476), or use _{(and I hate to say this, because this function is so often abused it's not even funny, but it's correctly applied here)} utf8_encode http://php.net/utf8_encode on all data you get from the database to convert it from Latin-1 to UTF-8.

所以要么：

// set the connection charset
mysql_set_charset('utf8');

$result = mysql_query("SELECT post_status, post_title FROM wp_posts");

$data = array();
while ($row = mysql_fetch_assoc($result)) { 
    $data['posts'][] = $row;
} 

$json_string = json_encode($data);

...

or:

$result = mysql_query("SELECT post_status, post_title FROM wp_posts");

$data = array();
while ($row = mysql_fetch_assoc($result)) { 
    $row = array_map('utf8_encode', $row);
    $data['posts'][] = $row;
} 

$json_string = json_encode($data);

...