PHP Fetch data twice - php

Question

My function looks like that.
private function generateTree($courseID) {
$q = "SELECT l.id, l.name AS lesson_name, c.name AS course_name FROM lessons AS l, courses AS c WHERE l.course_id=c.id AND c.id=?";
$stmt = $this->db->prepare($q);
$stmt->bind_param("i", $courseID);
$stmt->execute();
$stmt->store_result();
if ($stmt->num_rows > 0) {
$stmt->bind_result($id, $lName, $cName);
echo "<li> <a href='#'>$cName</a> <ul>";
while ($stmt->fetch()) <====HERE!!!
echo "<li> <a href='?course=$courseID&lesson=$id'> $lName </a></li>";
echo "</ul> </li>";
}
}
The problem is that I'm starting to fetch data inside a while condition, but I need it before the while, too. Can I fetch data twice? Any other suggestions?

Answer 1

It's been four years, but in case someone stumble upon this question like I did:
while ($stmt->fetch()) {
// do your thing
}
$stmt->data_seek(0);
while ($stmt->fetch()) {
// do something other
}
You can read documentation here

Answer 2

You can use fetchAll() to fetch all the data and iterate over it as many times as you want.
$result = $stmt->fetchAll(); // PDO
$result = $stmt->fetch_all(); // MySQLi
foreach($result as $row) { print $row['lesson_name']; }
foreach($result as $row) { print $row['lesson_name']; }
foreach($result as $row) { print $row['lesson_name']; }
etc...
Update: I'm not entirely sure what you are doing as you seem to have several ideas mixed into your code. Perhaps you want something like this?
$q = "SELECT l.id, l.name AS lesson_name, c.name AS course_name FROM lessons AS l, courses AS c WHERE l.course_id=c.id AND c.id=?";
$stmt = $this->db->prepare($q);
$stmt->bind_param("i", $courseID);
$stmt->execute();
if ($stmt->num_rows > 0)
{
$results = $stmt->fetch_all();
foreach($results as $row)
{
print_r($row);
}
}

Answer 3

I think you can make your database query class in a way that it returns an array of database result. You can use data as many times you want.
You can make an array of the database-resultset like this:
while($row = mysql_fetch_assoc($result))
{
$results[] = $row;
}