Thanks everyone for your help! Happy New Year. On Dec 21, 6:24 am, Roberta <[email protected]> wrote: > select * > from link_table le > where le.link_site = '3' or le.linked_site ='3' > and not exists (select 0 > from link_table li > where li.link_site = le.linked_site > and le.link_site = li.linked_site) > > 2009/12/18 Ease Bus <[email protected]> > > > Please help me with finding a SQL select statement for the following > > problems. > > > I have two classes: Site and Link > > > Table Link has two columns: linking_site_id, and linked_site_id > > > I would like to find all the links in table Link where linking_site_id > > = 3 or linked_site_id = 3 but only include a link where linked_site_id > > = 3 if the linking_site_id in that link is not one of the > > linked_site_id that site 3 links to. For example, if the Link table > > contains the following rows > > > Linking_site Linked_site > > 2 1 > > 3 2 > > 3 4 > > 5 3 > > 2 3 > > > What SQL select statement would return only the following: > > > 3 2 > > 3 4 > > 5 3 > > > If SQL query alone cannot do this, what is the most efficient way to > > do it via RoR? Thanks. > > > Thanks. > > > -- > > > You received this message because you are subscribed to the Google Groups > > "Ruby on Rails: Talk" group. > > To post to this group, send email to [email protected]. > > To unsubscribe from this group, send email to > > [email protected]<rubyonrails-talk%[email protected]> > > . > > For more options, visit this group at > >http://groups.google.com/group/rubyonrails-talk?hl=en. > >
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