я есть следующее:

    $ARTIFACT_NAME = $_POST['ArtifactName'];
    $ARTIFACT_TYPE = $_POST['ArtifactType'];
    $ARTIFACT_LOCATION = $_POST['ArtifactLocation'];
    $ARTIFACT_DOMAIN = $_POST['ArtifactDomain'];
    $ARTIFACT_AUTHOR = $_POST['ArtifactAuthor'];
    $ARTIFACT_LABEL = 'DB_'.$ARTIFACT_LOCATION.'_'.$ARTIFACT_DOMAIN.'_'.$ARTIFACT_NAME;
    $AUDIT_CONSTRAINTS = $_POST['AuditConstraints'];
    $SECURITY_CONSTRAINTS = $_POST['SecurityConstraints'];
    $REGISTERED_EMAIL = $_SERVER['HTTP_REMOTE_USER'];
    $REGISTERED_TIMESTAMP = "to_date('15-08-2011 14:32:37', 'DD-MM-YYYY HH24:MI:SS')";

    $query =    "INSERT INTO ".$db_schema.".ARTIFACTS (ARTIFACT_ID, ARTIFACT_NAME, ARTIFACT_TYPE, ARTIFACT_LOCATION, ARTIFACT_DOMAIN, ARTIFACT_AUTHOR, ARTIFACT_LABEL, AUDIT_CONSTRAINTS, SECURITY_CONSTRAINTS, REGISTERED_EMAIL, REGISTERED_TIMESTAMP)
                VALUES (:bind1, :bind2, :bind3, :bind4, :bind5, :bind6, :bind7, :bind8, :bind9, :bind10, :bind11)";
    $statement = oci_parse($connection, $query);

    oci_bind_by_name($statement, ":bind1", $ARTIFACT_ID);
    oci_bind_by_name($statement, ":bind2", $ARTIFACT_NAME);
    oci_bind_by_name($statement, ":bind3", $ARTIFACT_TYPE);
    oci_bind_by_name($statement, ":bind4", $ARTIFACT_LOCATION);
    oci_bind_by_name($statement, ":bind5", $ARTIFACT_DOMAIN);
    oci_bind_by_name($statement, ":bind6", $ARTIFACT_AUTHOR);
    oci_bind_by_name($statement, ":bind7", $ARTIFACT_LABEL);
    oci_bind_by_name($statement, ":bind8", $AUDIT_CONSTRAINTS);
    oci_bind_by_name($statement, ":bind9", $SECURITY_CONSTRAINTS);
    oci_bind_by_name($statement, ":bind10", $REGISTERED_EMAIL);
    oci_bind_by_name($statement, ":bind11", $REGISTERED_TIMESTAMP);

Что дает следующую ошибку:

ORA-01858: a non-numeric character was found where a numeric was expected

Однако, если я просто не связываю$REGISTERED_TIMESTAMP и вставьтеto_date в$query напрямую - отлично работает

В чем дело?! Это сводит меня с ума!