Message-ID: <49FDCB61.6020206@ultimeth.com>
Date: Sun, 03 May 2009 09:50:41 -0700
From: "Dean Gibson (DB Administrator)" <postgresql@ultimeth.com>
Organization: UltiMeth Systems
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To: pgsql-sql@postgresql.org
Subject: Creating a RULE for UPDATing a VIEW
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Using PostgreSQL version 8.3.0:

For various reasons, I have a number of VIEWs that are (except for the 
schema/table/view names) automatically generated as identity mappings of 
corresponding TABLEs;  eg:

CREATE VIEW public.yyy AS SELECT * FROM private.zzz;

Since we don't have updatable VIEWS yet, I tried:

CREATE RULE _update AS ON UPDATE TO public.yyy DO INSTEAD
  UPDATE private.zzz SET (*) = NEW.* WHERE key_field = OLD.key_field;

In order to make the automatic generation easy, I'm trying to make the 
syntax as general as possible, in particular, so that I don't have to 
list all of the column names (that appears to work).  However, the above 
(and other ingenious, but also incorrect, syntaxes) produces an error 
message.  So, I tried:

CREATE RULE _update AS ON UPDATE TO public.yyy DO INSTEAD
  (DELETE FROM private.zzz WHERE key_field = OLD.key_field;
   INSERT INTO private.zzz VALUES( NEW.*) );

This is syntactically accepted, but when I attempt to UPDATE a row, the 
old row is deleted but the new row is not inserted.  Manually listing 
the NEW.columns in place of "NEW.*" doesn't help.

-- Dean

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