As in my previous post, the same thing applies when using conversion functions in CLOB columns.
Probably the same thing will occur to any conversion function that you use.
So, this wont work
SELECT ... TO_CHAR(MY_CLOB) ...
$my_clob = OCIResult($stmt,"MY_CLOB");
But this will:
SELECT ... TO_CHAR(MY_CLOB) AS MYC ...
$my_clob = OCIResult($stmt,"MYC");
Best regards.