Query to list all the databases that have a specific user
By using this inner join and the link is database_id = principal_id
select 
dp.[name] as username,
dp.create_date,
dp.modify_date,
dp.[type_desc] as [type],
dp.authentication_type_desc as authentication_type,
dp.principal_id,
m.[name]
from sys.database_principals dp
INNER JOIN master.sys.databases m ON m.database_id = dp.principal_id
    AND m.name like '%PRD%'
where dp.[type] not in ('A', 'G', 'R', 'X')
and dp.[sid] is not null
and dp.[name] &lt;&gt; 'guest'
and dp.[name] = 'user_1'
order by username;

Also try to avoid != and replace it by &lt;&gt;.
Hope it helps,