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From: Melinda Hall <melinda@xdiv.lanl.gov>
To: postgres@postgres.Berkeley.EDU
Subject: POSTGRES class manipulation
Date: Fri, 28 Jul 1995 13:59:26 -0600
Message-ID: <199507281959.NAA15724@xdiv.lanl.gov> (raw)


----- Begin Included Message -----

From melinda@xdiv.lanl.gov Thu Jul 27 19:04:38 1995
Date: Thu, 27 Jul 1995 19:04:36 -0600
From: Melinda Hall <melinda@xdiv.lanl.gov>
To: melinda@lanl.gov
Subject: POSTGRES class manipulation - comp.databases #149
Content-Length: 1377

In article <3v97q1$65b@newshost.lanl.gov>, melinda@lanl.gov (Melinda Hall) writes:
|> I am using the POSTGRES relational database management system and I have run
|> into a problem concerning manipulation of classes within the database.
|> 
|> 
|> I currently have a number of classes, Class A, Class B, and Class C.  Each class has 20 fields, all with about 130 instances. (Some of the column names are different, some are the same.)
|> 
|> I'm trying to make one class out of this, combining the three classes. I want this class to have three rows; one for Class A, one for B, one for C. For each field that appears in any class, I want a vector of the original instances in that instance. (For |> example; If Class A and Class B both have field "foo" and 130 instances, and Class C does not have "foo", then in the final class, there should be a field foo, with the vector of A's instances in the cell at column foo and row 1, a vector of B's instances|>  in column foo, row 2, and NULL in column foo, row 3.) So before, I had three 130 row x 20 column tables; now, I want one 3 row x (# of unique columns) column table. 
|> 
|> Does anybody have an idea of how to do this, or where I can look for better information? I've gone through all of the manuals, and I just can't seem to figure this out. 
|> 
|> Thanks. Please e-mail me (melinda@lanl.gov) and post any thoughts. 


----- End Included Message -----


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