How to get multiple rows from mysql & PHP with this function - php

Question

I have this function which returns only one row, How can I modify the function so that it returns more than one row?
public function getVisitors($UserID)
{
$returnValue = array();
$sql = "select * from udtVisitors WHERE UserID = '".$UserID. "'";
$result = $this->conn->query($sql);
if ($result != null && (mysqli_num_rows($result) >= 1)) {
$row = $result->fetch_array(MYSQLI_ASSOC);
if (!empty($row)) {
$returnValue = $row;
}
}
return $returnValue;
}

Answer 1

There is a function in mysqli to do so, called fetch_all(), so, to answer your question literally, it would be
public function getVisitors($UserID)
{
$sql = "select * from udtVisitors WHERE UserID = ".intval($UserID);
return $this->conn->query($sql)->fetch_all();
}
However, this would not be right because you aren't using prepared statements. So the proper function would be like
public function getVisitors($UserID)
{
$sql = "select * from udtVisitors WHERE UserID = ?";
$stmt = $mysqli->prepare($sql);
$stmt->bind_param("s", $UserID);
$stmt->execute();
$res = $stmt->get_result();
return $res->fetch_all();
}

Answer 2

I would suggest storing them in an associative array:
$returnValue = array();
while($row = mysqli_fetch_array($result)){
$returnValue[] = array('column1' => $row['column1'], 'column2' => $row['column2']); /* JUST REPLACE NECESSARY COLUMN NAME AND PREFERRED NAME FOR ITS ASSOCIATION WITH THE VALUE */
} /* END OF LOOP */
return $returnValue;
When you call the returned value, you can do something like:
echo $returnValue[0]['column1']; /* CALL THE column1 ON THE FIRST SET OF ARRAY */
echo $returnValue[3]['column2']; /* CALL THE column2 ON THE FOURTH SET OF ARRAY */
You can still call all the values using a loop.
$counter = count($returnValue);
for($x = 0; $x < $counter; $x++){
echo '<br>'.$rowy[$x]['column1'].' - '.$rowy[$x]['column2'];
}