调用未定义的方法mysqli_stmt :: free（）

Question

I want to prepare a mysql script that first checks the id of the user based on given email and later on use this found id in the next query. What I did so far is as follows:

$find_id  = "SELECT id from client 
         WHERE email = ? ";
$statement = $mysqli->prepare($find_id);
$statement->bind_param("s", $client_mail);
$statement->execute();
$statement->bind_result($id);
$statement->free();

$sql  = "SELECT client_name, contact_name from client_addr 
         WHERE client_id = ? AND is_actual < ? ";

$stmt = $mysqli->prepare($sql);
$stmt->bind_param("is", $id, "Y");
$stmt->execute();
$result = $stmt->get_result()->fetch_all(MYSQLI_ASSOC);
echo json_encode($result);

but now I'm getting the error related to this line:

$statement->free();

that says Call to undefined method mysqli_stmt::free() in. However, when I remove this line I'm getting the error:

Uncaught exception 'mysqli_sql_exception' with message 'Commands out of sync; you can't run this command now' 

on this line:

$stmt = $mysqli->prepare($sql);

How can I fix it?

Answer 1

I believe the function you're trying to use would be mysqli_stmt::free_result().
You'll need to change this line:

$statement->free();

To:

$statement->free_result();

The second Uncaught exception occurs because mysqli is an unbuffered SQL query handler, so you should store your results if you're looping simultaneous executions with something like $stmt->store_result(); and then you can unload the mysqli buffer to state a new query.