How to create Google Chart friendly JSON arrays from MySQL? - php

Question

I think I'm close to completing the passing of MySQL data to Google Charts through JSON/AJAX. I am able to output a JSON string in the correct format but it is not outputting any SQL data. I've searched everywhere for a solution with no results. Anyone see what is missing from the code?
JSON output
{"cols":[{"id":"","label":"projid","type":"string"},{"id":"","label":"hours","type":"number"}],"rows":[{"c":[{"v":""},{"v":0}]},{"c":[{"v":""},{"v":0}]},{"c":[{"v":""},{"v":0}]},{"c":[{"v":""},{"v":0}]},{"c":[{"v":""},{"v":0}]},{"c":[{"v":""},{"v":0}]},{"c":[{"v":""},{"v":0}]},{"c":[{"v":""},{"v":0}]},{"c":[{"v":""},{"v":0}]}]}
PHP->JSON
<?php
// -----> Query MySQL and parse into JSON below. <------
// write your SQL query here (you may use parameters from $_GET or $_POST if you need them)
require_once ("Includes/session.php");
require_once ("Includes/simplecms-config.php");
require_once ("Includes/connectDB.php");
$recId = null;
$projid = null;
$hours = null;
$recId = $_GET['id'];
$projid = $_GET['projid'];
$hours = $_GET['hours'];
$query = "SELECT projid, hours FROM hours WHERE id = ?";
$statement = $databaseConnection->prepare($query);
$statement->bind_param('d', $recId);
$statement->execute();
$results = $statement->get_result();
$rows = array();
$table = array();
$table['cols'] = array(
array('id' => "",'label' => 'projid', 'type' => 'string'),
array('id' => "",'label' => 'hours', 'type' => 'number')
);
/* Extract the information from $result */
while ($r = $results->fetch_assoc()) {
$temp = array();
// The following line will be used to slice the Pie chart
$temp[] = array('v' => (string) $r['projid']);
// Values of each slice
$temp[] = array('v' => (int) $r['hours']);
$rows[] = array('c' => $temp);
}
$table['rows'] = $rows;
// convert data into JSON format
$jsonTable = json_encode($table);
echo $jsonTable;
?>

Answer 1

The following code returned the correct array for Google Charts. Google Charts - JSON Data
<?php
// -----> Query MySQL and parse into JSON below. <------
require_once ("Includes/connectDB.php");
$result = $databaseConnection->query("SELECT projid, hours FROM alloc_hours");
$table = array();
$table['cols'] = array(
array('id' => "", 'label' => 'projid', 'pattern' => "", 'type' => 'string'),
array('id' => "", 'label' => 'hours', 'pattern' => "", 'type' => 'number')
);
$rows = array();
while ($nt = $result->fetch_assoc())
{
$temp = array();
$temp[] = array('v' => $nt['projid'], 'f' =>NULL);
$temp[] = array('v' => $nt['hours'], 'f' =>NULL);
$rows[] = array('c' => $temp);
}
$table['rows'] = $rows;
$jsonTable = json_encode($table);
echo $jsonTable;
?>
Array
{"cols":[{"id":"","label":"projid","pattern":"","type":"string"},{"id":"","label":"hours","pattern":"","type":"number"}],"rows":[{"c":[{"v":"2","f":null},{"v":"8","f":null}]},{"c":[{"v":"1","f":null},{"v":"6","f":null}]},{"c":[{"v":"3","f":null},{"v":"20","f":null}]},{"c":[{"v":"2","f":null},{"v":"10","f":null}]},{"c":[{"v":"4","f":null},{"v":"5","f":null}]},{"c":[{"v":"1","f":null},{"v":"30","f":null}]}]}

Answer 2

Try replacing this line:
$statement->store_result();
with:
$results = $statement->get_result();
and replace the foreach loop with a while loop:
while ($r = $results->fetch_assoc()) {
$temp = array();
// The following line will be used to slice the Pie chart
$temp[] = array('v' => (string) $r['projid']);
// Values of the each slice
$temp[] = array('v' => (int) $r['hours']);
$rows[] = array('c' => $temp);
}
That should get the query to return results. You don't need the lines:
$statement->bind_result($projid, $hours);
$statement->fetch();