mysql: value can be "null", but not must be "specific_value"

I have a query like this:

SELECT group.active, group.desc,
group.group_id, hide_group.hide,
hide_group.user_id
FROM group 
LEFT JOIN hide_group ON
     group.group_id=hide_group.group_id
WHERE group.active=1 
AND hide_group.user_id != 'test' 
OR hide_group.user_id IS NULL   
ORDER BY hide_group`.`user_id`  DESC

This completely ignores the active row for some reason? If I remove

and hide_group.user_id!='test'

It takes active=1 into account, but does not return right values. If I examine the first query, everything would be ok if the active condition w开发者_StackOverflow中文版ould be taken into account. Help!

Use the parentheses in the correct way when you deal with "and" and "or" together.

table name group, field name desc would not help