<?php
$sql = 'SELECT "a" AS Source UNION ALL
SELECT "b" AS Source UNION ALL
SELECT "c" AS Source UNION ALL
SELECT "d" AS Source UNION ALL
SELECT "e" AS Source UNION ALL
SELECT "f" AS Source UNION ALL
SELECT "g" AS Source ';
$result = $mysqli->query($sql);
if ($result->num_rows > 0) {
while ($row = $result->fetch_assoc()) {
foreach ($row as $k => $v) {
if ($k == 'Source') {
$seriesData[] = "'{$v}'";
}
}
}
echo implode(',', $seriesData);
}