WP3 Authorisation Steve Fisher / RAL 2/4/2003. WP3 Steve Fisher/RAL - 2/4/2003Authorisation2 I...
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WP3 Authorisation Steve Fisher / RAL 2/4/2003 <s.m.fisher@ rl .ac. uk >
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Transcript of WP3 Authorisation Steve Fisher / RAL 2/4/2003. WP3 Steve Fisher/RAL - 2/4/2003Authorisation2 I...
Steve Fisher/RAL - 2/4/2003Authorisation 2
WP3
I don’t think I disagree(much) with Linda• Control must be at the level of views on the
database– Very compact– Very powerful
Steve Fisher/RAL - 2/4/2003Authorisation 3
WP3Example - people
• Doctor: Select sanity for his patients• Anybody: select average salary for people in GB• Friend: phone number
People
Name Address Phone # Salary Sanity Doctor
Fred GB 1 6 0.1 Seuss
Bill CH 3 60 0.5 Spock
Mary D 4 50 0.9 Spock
Steve Fisher/RAL - 2/4/2003Authorisation 4
WP3Example - doctor
• View– Name, Address, Phone, Sanity from People where Doctor =
“Spock”– Name, Address, Phone, Sanity from People where Doctor = “{DN}”
• Good Query– Select Name, Sanity from People where Doctor = “Spock”
• Bad Query– Select Name, Salary from People where Doctor = “Spock”
• What about– Select Name, Sanity from People where Name = “Bill”
People
Name Address Phone # Salary
Sanity Doctor
Fred GB 1 6 0.1 Seuss
Bill CH 3 60 0.5 Spock
Mary D 4 50 0.9 Spock
Doctor: Select sanity for his
patients
Steve Fisher/RAL - 2/4/2003Authorisation 5
WP3Example - doctor
• View– Name, {AGGREGATE}(Salary) where Country = “{*}”
• Good Query– Select Avg(Salary) from People where Country = “GB”
People
Name Address Phone # Salary
Sanity Doctor
Fred GB 1 6 0.1 Seuss
Bill CH 3 60 0.5 Spock
Mary D 4 50 0.9 Spock
Anybody: select average salary for people in GB
Steve Fisher/RAL - 2/4/2003Authorisation 6
WP3Example - doctor
• View– P.Name, P.Phone, P.Address from People P, Friend F where
P.Name = F.Name and F.Friend = “{DN}”
• Good Query– Select P.Name, P.Phone from People P, Friend F where P.Name =
F.Name and F.Friend = “Mary” and P.Name=“Bill”
• Bad Query– Select P.Name, P.Phone from People P, Friend F where P.Name =
F.Name and F.Friend = “Bill” and P.Name=“Mary”
People
Name Address Phone # Salary
Sanity Doctor
Fred GB 1 6 0.1 Seuss
Bill CH 3 60 0.5 Spock
Mary D 4 50 0.9 Spock
Friend: phone number
Friend
Name Friend
Fred Bill
Bill Fred
Bill Mary
