Description:
------------
When I try to insert a space ' ' in a table with a not null value PDO_OCI throws an ORA-01400: cannot insert NULL exception. I know Oracle uses blank spaces as nuls but in this example there is not a blank space. I realice that the same problem occurs not only with a ' '. Even with more spaces. It looks that trims the value before send it to the database ('1 ' => '1').

Reproduce code:
---------------
<?php
// create table WEB.TBLDUMMY (COL1 VARCHAR2(3) not null)
$db = new PDO(
    $dsn, // my DB dsn
    $user, // database username
    $password); // database password
try {
    $db->setAttribute(PDO::ATTR_AUTOCOMMIT, false);
    $db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    $db->beginTransaction();
    $stmt = $db->prepare("INSERT INTO WEB.TBLDUMMY (COL1) VALUES (:COL1)");
    $stmt->bindValue(':COL1', ' ');
    $stmt->execute();
    $db->commit();
} catch (Exception $e) {
    echo $e->getMessage();
}

Expected result:
----------------
Nothing. The script must finish without output

Actual result:
--------------
SQLSTATE[HY000]: General error: 1400 OCIStmtExecute: ORA-01400: cannot insert NULL into ("WEB"."TBLDUMMY"."COL1")
 (/opt/PDO_OCI-1.0/oci_statement.c:142)