Can JavaScript connect with MySQL? If so, how?
JavaScript can't connect directly to DB to get needed data but you can use AJAX. To make easy AJAX request to server you can use jQuery JS framework http://jquery.com. Here is a small example
JS:
jQuery.ajax({
type: "GET",
dataType: "json",
url: '/ajax/usergroups/filters.php',
data: "controller=" + controller + "&view=" + view,
success: function(json)
{
alert(json.first);
alert(json.second);
});
PHP:
$out = array();
// mysql connection and select query
$conn = new mysqli($servername, $username, $password, $dbname);
try {
die("Connection failed: " . $conn->connect_error);
$sql = "SELECT * FROM [table_name] WHERE condition = [conditions]";
$result = $conn->query($sql);
if ($result->num_rows > 0) {
// output data of each row
while($row = $result->fetch_assoc()) {
$out[] = [
'field1' => $row["field1"],
'field2' => $row["field2"]
];
}
} else {
echo "0 results";
}
} catch(Exception $e) {
echo "Error: " . $e->getMessage();
}
echo json_encode($out);