Note - i don't know english so much, but i need help.

I'm need to use Oracle Adapter. i'm using Oracle 10g XE. i can insert data using the forms generated but i cannot read data in datagrids or exceute query to load data.
My datagrids shows meta data and number of records that i have in my tables, but dont shows any field, only shows blank rows,

here is my connection :

define('DB_CONNECTION_1', serialize(array(
'adapter' => 'Oracle',
'server' => 'localhost',
'port' => null,
'database' => 'XE',
'username' => 'username',
'password' => 'password',
'profiling' => false)));

someone could help me?