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From:Marco Carbone Date:April 18 2006 3:38pm
Subject:select records not in a *particular* many-to-many relationship
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Hey all,

I've checked the archives and found an explanation as to how the check 
if a record is not in a many-to-many table.  The answer to that is 
somewhat simple and clear to me.  But here's my problem: how do you 
check if a record doesn't have a *particular* many-to-many 
relationship?  As in, let's say I have three tables: users, groups, and 
users_groups linking the two in a many-to-many relationship.  Now let's 
say that I want to select all users who are not in the group "Group1" -- 
that is, that user may have entries in the users_groups table, but they 
would be for other groups, not "Group1."

One more thing: this is easily done with subqueries, but for performance 
reasons, I need to do it with explicit joins.  Anyone know how I can do 
this?

Thanks,
marco

-- 
Marco Carbone
Webmaster/Web Developer
Committee to Regulate and Control Marijuana
http://www.regulatemarijuana.org

Thread
select records not in a *particular* many-to-many relationshipMarco Carbone18 Apr
  • Re: select records not in a *particular* many-to-many relationshipPeter Brawley18 Apr
    • Re: select records not in a *particular* many-to-many relationshipgerald_clark18 Apr
      • Re: select records not in a *particular* many-to-many relationshipMarco Carbone18 Apr