This is an example of returning the primary key from an insert so that you can do inserts on other tables with foreign keys based on that value. The date is just used to provied semi-unique data to be inserted.
$conn = oci_connect("username", "password")
$stmt = oci_parse($conn, "INSERT INTO test (test_msg) values (:data) RETURN test_id INTO :RV");
$data = date("d-M-Y H:i:s");
oci_bind_by_name($stmt, ":RV", $rv, -1, SQLT_INT);
oci_bind_by_name($stmt, ":data", $data, 24);
oci_execute($stmt);
print $rv;