Question

I have a little (and stupid) problem: I’m building a PHP application using mysqli and a MySQL server. When the application is loaded, a variable called $database is initialized using

$database = new mysqli($dbHost, $dbUser, $dbPassword, $dbName);

This, of course, works perfectly. If I create an statement to do a query:

$stmt = $database->prepare('SELECT a, b, c FROM table WHERE a = ?');

This still works. But, if I try to create another statement without closing the previous one, sometimes works, and sometimes now. The error I get when the creation of the statement fails is:

Fatal error: Call to a member function bind_param() on a non-object

And my question is: why? What should I do, open a connection (new mysql(…)) every time I want to create a new statement (and I have another open)?

Example

$stmt = $database->prepare('SELECT a, b, c FROM table WHERE a = ?');
$stmt->bind_param('i', $aValue);
$stmt->execute();
/* do some other operations, without closing $stmt */
$stmt2 = $database->prepare('INSERT INTO table2 (e, f) VALUES (? ,?)');
// Now, $stmt2 isn't initialized, so when the next line is run, the app fails
$stmt2->bind_param('ss', $someValue, $anotherValue);

If, before the

$stmt2 = $database->prepare('INSERT INTO table2 (e, f) VALUES (? ,?)');

I add a simple

$stmt->close();

All works without any problems. So, what is the problem?

Answer 1

You cannot run another query until you have fetched all the results from the previous. Otherwise you will have to make a separate connection.