Question

Why it stops to work on second $mysqli->prepare($query) statement?

$mysqli = @new mysqli(HOSTNAME, USERNAME, PASSWORD, DATABASE);
...
if ($stmt = $mysqli->prepare($query)) {
    // Code is working fine
    ...
    if ($stmt2 = $mysqli->prepare($query2)) {
        // Code does not work
        ...
    }
}

And work fine with repeated mysqli connection:

$mysqli = @new mysqli(HOSTNAME, USERNAME, PASSWORD, DATABASE);
$mysqli2 = @new mysqli(HOSTNAME, USERNAME, PASSWORD, DATABASE);
...
if ($stmt = $mysqli->prepare($query)) {
    // Code is working fine
    ...
    if ($stmt2 = $mysqli2->prepare($query2)) {
        // Code is working fine
        ...
    }
}

How to avoid repeated mysqli connection for second prepare statement?

---

Update: As I see the community wants a real example:

db table fruits with data:

CREATE TABLE IF NOT EXISTS `fruits` (
  `id` varchar(8) NOT NULL,
  `group` varchar(8) NOT NULL,
  `name` varchar(250) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8;

INSERT INTO `fruits` (`id`, `group`, `name`) VALUES
('03E7', '', 'Berries'),
('0618', '03E7', 'blueberry'),
('051B', '03E7', 'raspberry'),
('02AA', '03E7', 'strawberry'),
('035F', '', 'Citrus'),
('07A5', '035F', 'grapefruit'),
('0633', '035F', 'lime'),
('05E1', '', 'Pear');

php script:

<?php

$mysqli = new mysqli('localhost', 'root', 'password', 'test');
//$mysqli2 = new mysqli('localhost', 'root', 'password', 'test');

$query1 = "SELECT id, name FROM fruits WHERE `group`=''";
$query2 = "SELECT name FROM fruits WHERE `group`=?";

$stmt1 = $mysqli->stmt_init();
$stmt2 = $mysqli->stmt_init();
//$stmt2 = $mysqli2->stmt_init();

if($stmt1->prepare($query1)){
    $stmt1->execute();
    $stmt1->bind_result($id, $name1);

    while($stmt1->fetch()){
        echo $name1;

        if($stmt2->prepare($query2)){
            $stmt2->bind_param('s', $group);
            $group = $id;
            $stmt2->execute();
            $stmt2->bind_result($name2);

            echo ':';

            while($stmt2->fetch()){
                echo ' ' . $name2 . ',';
            }
        }

        echo '<br>';
    }
}

?>

Result:

Berries
Citrus
Pear

Expected result:

Berries: blueberry, raspberry, strawberry,
Citrus: grapefruit, lime,
Pear:

Answer 1

To fix the issue remove

$stmt1 = $mysqli->stmt_init();
$stmt2 = $mysqli->stmt_init();

and add after $stmt1->execute();

$stmt1->store_result();

and replace $stmt1->prepare($query1), $stmt2->prepare($query1) with

$stmt1 = $mysqli->prepare($query1)
$stmt2 = $mysqli->prepare($query2)