How to download in CSV using API

[vipera7]

Hello,

I'm trying to download a report in csv using API.
I found the endoit (I hope it's the right one):

POST /api/dataset/:export-format
Execute a query and download the result data as a file in the specified format.

PARAMS:
export-format value must be one of: api, csv, json, xlsx.

query value must be a valid JSON string.

visualization_settings value must be a valid JSON string.

I wrote it in PHP :

public function DownloadCSV($token, $query, $exportFormat) {
    if($exportFormat == "api" or $exportFormat == "csv" or $exportFormat == "json" or $exportFormat == "xlsx"){
        $ch = curl_init();
	//https://github.com/metabase/metabase/blob/master/docs/api/dataset.md
	var_dump($this->MetabaseURL.'/api/dataset/'.$exportFormat);
	curl_setopt($ch, CURLOPT_URL, $this->MetabaseURL.'/api/dataset/'.$exportFormat);
	curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
	curl_setopt($ch, CURLOPT_CUSTOMREQUEST, 'POST');
	curl_setopt($ch, CURLOPT_POSTFIELDS, "query=$query");

	$headers = array();
	$headers[] = 'Content-Type: application/json';
	$headers[] = 'X-Metabase-Session: '.$token;
	curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);

	$result = curl_exec($ch);
	if (curl_errno($ch)) {
		echo 'Error:' . curl_error($ch);
	}
	curl_close($ch);
	file_put_contents("text.txt", $result);
	return $result;
 }
	 }

Output :

string 'http://localhost:3000/api/dataset/csv' (length=37)
string 'Malformed JSON in request body.' (length=31)

The query contain a SQL request.

How do I format query and visualization_settings ?

And i'll like to update the data before exporting, how can I update the data ?
Thanks

[flamber]

Please use the forum for questions and troubleshooting: https://discourse.metabase.com/