Posted to tcl by kbk at Tue Dec 07 13:02:08 GMT 2010view pretty
select distinct email, registered from thetable where registered = 1 and onlist = 1 -- people who are registered. -- you didn't specify what happens if -- someone is registered twice, once -- 'onlist' and once not. union select distinct o.email as email, 0 as registered from thetable o left outer join thetable i on i.email = o.email and i.registered = 1 where i.email is null and o.registered = 0 and o.onlist = 1 group by email, registered -- people who are not registered, -- you didn't specify what to do if -- an unregistered person is both -- onlist and not onlist