php mysqli_insert_id($link) convert/retain

Question

Hi i have a form (X) that inserts data into a mysql table (A) and than redirects to another form (Y) which will insert data into another table (B) but i need to use tables A's last inserted row.

I know i can get it from using the mysqli_insert_id function but when i submit to form Y and re show form Y is messes up because the $ID value is nulled. i tried to type cast the value of id by doing this.

$id = (int)mysqli_insert_id($link);

but that didn't help at all.

Answer 1

You could use sessions to store the value whilst you're processing form X, which can then be picked up by form Y.

X:

session_start();
$_SESSION['insert_id'] = 42;

Y:

session_start();
$insert_id = $_SESSION['insert_id']; // 42

See the manual for an example of how to destroy the session after you're done with it.

Answer 2

You'll have to persist the results from mysqli_insert_id between forms, either via cookies, session or hidden inputs.

As mysqli_insert_id will only return for the connection instance it's called on, rather than the database as a whole, when you shift to another form, the original connection will closed, and a new one opened, which has not inserted any id's (Hence the null value).

I'd personally go with session, but it all depends on your security requirements.