My PHP setup is a standard RH 7.2 PHP installation. After trying to open a MySQL database using the PEAR database abstraction layer, using a username that does not exists and no password (but an existing database), I get the following error object:

db_error Object
(
    [error_message_prefix] => 
    [error_prepend] =>  
    [error_append] => 
    [mode] => 1
    [level] => 1024
    [code] => -1
    [message] => DB Error: unknown error
    [debuginfo] =>
    [userinfo] => mysql://webuser@localhost/DSI
    [callback] => 
)

However, db::isError() returns *FALSE* on this object. Thus, I cannot distinguish whether the database connection has been established or not.