I have a table with many columns. I need to query three of the fields siteid, roleid and userid. For each siteid, there may be multiple userids. If there is a userid there is one roleid. For two users, I am trying to compare the siteid there have access to and their role. I want one row for each site. On each row I want to know if the each of the users has access and their role. If they do not have access to either siteid, I do not want that siteid to appear in the results.