PHP Library to convert JSON to CSV?

Question

I've got a JSON service and need to create a script to export data to CSV files. Does anyone have a method or library you can suggest to migrate JSON to CSV format?

Here's an example format though I expect to have to retro-fit the solution to work with it:

{"service_name":
      { key : value, key : value....}
}

or:

{"service_name":
        [
               { key : value, key : value....},
               ...
         ]
}

Answer 1

i generally agree with the commenters, but if you're data is prepared this way, isn't this pseudo-code all you need?

$json_str = "{'aintlist':[4,3,2,1], 'astringlist':['str1','str2']}";

$json_obj = json_decode ($json_str);

$fp = fopen('file.csv', 'w');

foreach ($json_obj as $fields) {
    fputcsv($fp, $fields);
}

fclose($fp);

Answer 2

Something like this should work, assuming your JSON is an array of data sets without arrays or embedded objects:

$file = file_get_contents('http://example.com/blah/blah');
$json = json_decode($file);

$csvfile = fopen('file.csv', 'w+');
foreach ($json as $row) {
    $line = "'" . join("\",\"", $row) . "\"\n";
    fputs($csvfile, $line);
}
fclose($csvfile);

You'll have to add appropriate error handling. There are a lot of things that can go wrong when trying to do this sort of thing (i.e. JSON file not available or is malformatted, can't create new CSV file)

Answer 3

I just needed to do the same. I wrote the small command line script, which take as a parameter the json file and output the CSV.

You can check it here: PHP Converting JSON array to CSV

The important staff there is using keys of array as the first row in CSV file. And maintaining the order on the next elements, to not mess up the CSV.

Here is the code:

if (empty($argv[1])) die("The json file name or URL is missed\n");
$jsonFilename = $argv[1];

$json = file_get_contents($jsonFilename);
$array = json_decode($json, true);
$f = fopen('php://output', 'w');

$firstLineKeys = false;
foreach ($array as $line)
{
    if (empty($firstLineKeys))
    {
        $firstLineKeys = array_keys($line);
        fputcsv($f, $firstLineKeys);
        $firstLineKeys = array_flip($firstLineKeys);
    }
    // Using array_merge is important to maintain the order of keys acording to the first element
    fputcsv($f, array_merge($firstLineKeys, $line));
}