D3 JavaScript从mysql提取数据Uncaught typeError

Question

Im currently getting my data from a mysql database using this php :

<?php
    $username = "*****"; 
    $password = "******";   
    $host = "localhost";
    $database="db";

    $server = mysql_connect($host, $username, $password);
    $connection = mysql_select_db($database, $server);

    $myquery = "
SELECT  `this`, `that` FROM  `table`
";
    $query = mysql_query($myquery);

    if ( ! $query ) {
        echo mysql_error();
        die;
    }

    $data = array();

    for ($x = 0; $x < mysql_num_rows($query); $x++) {
        $data[] = mysql_fetch_assoc($query);
    }

    $fp = fopen('empdata.json', 'w');
    fwrite($fp, json_encode($data));
    fclose($fp);    

    mysql_close($server);
?>

I then run this html with the previous json file that I generated

d3.json("mypreviouslygeneratedjson.json", function (error, data) {

    data.forEach(function (d) 
    {
        ...
    }
...

It all goes well, I can generate bar charts, pie charts etc. But as soon as I replace the 3 fopen,fwrite and fclose lines with this line:

echo json_encode($data);

(plus I replace "mypreviouslygeneratedjson.json" with the php file that I mentioned before)

As soon as I try to do this, I get an error in the console:

Uncaught TypeError: Cannot read property 'forEach' of undefined

What is going on here? Im practically using the same json in both cases.

Answer 1

The problem was that the json generated by my php file included the following mysql warning in it :

Deprecated: mysql_connect(): The mysql extension is deprecated and will be removed in the future: use mysqli or PDO instead

This resulted in filling my json file with html, making it unreadable by the d3.json