Mysqli Bind dynamic parametere

Trying to create a function to insert data into a SQL table, using MySQLI. I want to create a generic function, to insert different types of data in different databases.
The issue is at binding the parameters. I can't find a good way to bind them, as I've got multiple variables with values and keys, but they're all in array format, and  bind_param  requires a new variable for each

$sql = 'SELECT id, lastname FROM customers WHERE ' .
  'category = ? AND ' .
  'lastname LIKE ?';

/* Prepare statement */
$stmt = $conn->prepare($sql); if($stmt === false) {
  trigger_error('Wrong SQL: ' . $sql . ' Error: ' . $conn->errno . ' ' . $conn->error, E_USER_ERROR);
}
 
$category_id = 1;
$lastname = '%Smith%';
 
/* Bind parameters. Types: s = string, i = integer, d = double,  b = blob */
$stmt->bind_param('is', $category_id, $lastname);
 
/* Execute statement */
$stmt->execute();
 
/* Fetch result to array */
$res = $stmt->get_result();
while($row = $res->fetch_array(MYSQLI_ASSOC)) {
  array_push($a_data, $row);
}

The problem
$stmt->bind_param() does not accept params array. So, how to bind params, if their number is variable, depending on user input in your application?

A workaround is to use call_user_func_array to pass dynamically the params array.

The solution
In the following code:

$conn is the connection object

$a_bind_params is the array of the parameters you want to bind

$a_param_type is an array with the type of each parameter (Types: s = string, i = integer, d = double, b = blob). This is another disadvantage of MySQLi API. You have to maintain this array some way in your application.

With call_user_func_array, array params must be passed by reference. See notes in manual page.

The code:

/* Bind parameters. Types: s = string, i = integer, d = double,  b = blob */
$a_params = array();
 
$param_type = '';
$n = count($a_param_type);
for($i = 0; $i < $n; $i++) {
  $param_type .= $a_param_type[$i];
}
 
/* with call_user_func_array, array params must be passed by reference */
$a_params[] = & $param_type;
 
for($i = 0; $i < $n; $i++) {
  /* with call_user_func_array, array params must be passed by reference */
  $a_params[] = & $a_bind_params[$i];
}
 
/* Prepare statement */
$stmt = $conn->prepare($sql);
if($stmt === false) {
  trigger_error('Wrong SQL: ' . $sql . ' Error: ' . $conn->errno . ' ' . $conn->error, E_USER_ERROR);
}
 
/* use call_user_func_array, as $stmt->bind_param('s', $param); does not accept params array */
call_user_func_array(array($stmt, 'bind_param'), $a_params);
 
/* Execute statement */
$stmt->execute();
 
/* Fetch result to array */
$res = $stmt->get_result();
while($row = $res->fetch_array(MYSQLI_ASSOC)) {
  array_push($a_data, $row);
}