Compliance data missing for computers in SCCM 2007 DB

I am trying to find all the patches that are missing on particular computer using SQL query. However some computers do not return any results. 

Does that mean compliance data is missing.

How could i find all the machines for which compliance data is missing and what can i do to fix them.

We are using SCCM 2007 SP2 R3

I use the following query for this

select distinct
   sys.Name0,
   ui.BulletinID as BulletinID,
   ui.ArticleID as ArticleID,
   ui.Title as Title,
   ui.Severity,ui.CustomSeverity,ui.DateRevised
   from v_UpdateComplianceStatus css
join v_UpdateInfo ui on ui.CI_ID=css.CI_ID
join v_R_System sys on css.ResourceID=sys.ResourceID
join v_ClientCollectionMembers ccm on ccm.ResourceID=sys.ResourceID
where  css.Status=2 and ccm.CollectionID='SMS00001'
AND Name0 like 'Comp001'
order by ui.Title