Hi guys!
I have some weird output from one of my SQL statements. Here it's is:

select count(*) from libvolumes where status='Private'
  Unnamed[1]
------------
        3698

Ok, so 3698 private volumes on this server. Now, how many contain data:

select count(*) from libvolumes where status='Private' and last_use = 'Data'
  Unnamed[1]
------------
        1011

Right, I know a lot of tapes do not have a value in the Last Use column (my 
guess it is that these are tapes created by SAN clients), so how many are there:

select count(*) from libvolumes where status='Private' and last_use != 'Data'
  Unnamed[1]
------------
           0

Huh? There should be 3698-1011=2687! Last_use is empty then?

select count(*) from libvolumes where status='Private' and last_use=NULL
  Unnamed[1]
------------
           0

I'm lost here... I'm I doing something wrong? The total of last_use='Data' and 
last_use!='Data' should be the same as the output from the query with no 
last_used specified, right?
Thanks for any help in advance!
Kind regards,
Eric van Loon

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