如何将simplesamlphp连接到Oracle数据库？

I have a simplesamlphp installed and successfully connected to a MySQL database, but now I need to connect to an Oracle database.

I used the following configuration in authsource.php

'example-sql' => array(
    'sqlauth:SQL',
    'dsn' => 'oci:dbname=//serverHost/databasename',
    'charset' => 'utf8',
    'username' => 'user',
    'password' => 'password',
    'query' => "SELECT UserIdentity, AccountType,
    FROM Users 
    WHERE UserIdentity = :userid 
    AND UserPassword =MD5(:password) ",
),

but I could not login. I received no errors.