> "Michael Richards" <michael@fastmail.ca> writes:
>> The reduction of the list doesn't seem to be terribly efficient.
>> Here are some strategies I've been looking at:
>
>> select id from users WHERE
>> id not in (select userid from sentletters where lettertype=1) AND
>> aclgroup IN (1,2);
>
> Try an EXCEPT, along the lines of
>
> (select id from users where conditions) except
> (select userid from sentletters where other-conditions);
I tried except but in this case I'd have to use this to extract the
list of ids and then re-join it with users again to get the rest of
the data from the users table :(
-Michael
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