Check for no more than two entries of each value in a column?
From: livefreeordie <jpittman2_at_gmail.com>
Date: Fri, 17 Apr 2009 10:38:48 -0700 (PDT)
Message-ID: <49e12403-1bf2-4f8f-ad0b-5fad65ad27d8_at_s21g2000vbb.googlegroups.com>
Hi,
Date: Fri, 17 Apr 2009 10:38:48 -0700 (PDT)
Message-ID: <49e12403-1bf2-4f8f-ad0b-5fad65ad27d8_at_s21g2000vbb.googlegroups.com>
Hi,
I need to create an app where any given employee may nominate up to TWO other employees per year for an award. This number could change.
Now I could create a table like this:
PK, U1 nominator (varchar2(12)) PK, U1 year (int) U1 nomination1_id (int) U1 nomination2_id (int)
Then another table:
PK nomination_id (int)
nominee (varchar2(12)) nomination_data ....
However, this would force me to update any Views or Code every time the number of allowed nominations changes.
I'd much rather do this:
PK nomination_id (int)
year (int) nominator (varchar2(12)) nominee (varchar2(12)) nomination_data ...
And have some kind of Check Constraint to only allow two nominees per nominator per year. But I don't know how to do that.
Thoughts?
~ Jamie Received on Fri Apr 17 2009 - 12:38:48 CDT