🚀 go-pugleaf

Uzytkownik "Jason Summers" <jason@grinc.org> napisal w wiadomosci 
news:4743bb74$1@newsgroups.borland.com...
> To do queries like that, you can use the IN and NOT IN.
>
> select * from EMPLOYEETABLE1 where EMPLOYEEID NOT IN (select EMPLOYEEID 
> from EMPLOYEETABLE2)
>
> Here's a few more examples of usage:
>
> // selects all contacts which have not been assigned to a group
> select CONTACTID from CONTACTS where CONTACTID NOT IN (select CONTACTID 
> from CONTACTGROUPMEMBERS)
>
> or
>
> // selects all contacts which are in a group
> select CONTACTID from CONTACTS where CONTACTID IN (select CONTACTID from 
> CONTACTGROUPMEMBERS)
>
> - Jason
>
> "Leonardo Tansini" <ltansini@katamail.com> wrote in message 
> news:op.t13wz0jinnuxdn@salaxp...
>> In my IB db I've two big employees tables whith the same structure and 
>> keys. I need to create a query to select the employees present in the 
>> first table that are not present in the second one. Some help? Regards.


above will be very slow on big tables
better is

select * from EMPLOYEETABLE1 E1 where
not exists(select FROM EMPLOYEETABLE2 E2 WHERE E1.EMPLOYEEID=E2.EMPLOYEEID)


Karol Bieniaszewski