*From:* amul sul *Sent:* Monday, January 02, 2017 12:42 PM *To:* Frank Millman *Cc:* pgsql-general *Subject:* Re: [GENERAL] Difficulty modelling sales taxes
> On Mon, Jan 2, 2017 at 4:03 PM, Frank Millman <frank@chagford.com <mailto:frank@chagford.com>> wrote: > > Hi all > > > > It is a bit ugly, because I have to use the ‘NVARCHAR code’ column from > > tax_codes, not the primary key, but I think it would work. > > > NVARCHAR ? Are you using PostgreSQL as database server? >
Oops, sorry.
I am testing with PostgreSQL and with SQL Server, so I was in the wrong mindset when I posted.
I should have said VARCHAR.
Frank
*First, there is no need to make row_id's when you already have a valid primary key.
In a perfect world yes, but this is a world with ORM's as I found out the hard way:
"The primary key field is read-only. If you change the value of the primary key on an existing object and then save it, a new object will be created alongside the old one."
You are quoting from a django document. Please don't muddle the waters. So you are saying this will not work? UPDATE mytable SET mykey = 'new_value' WHERE mykey = 'old_value';
DELETE FROM mytable WHERE mykey = 'old_value';
Happy New Year Adrian
--
Melvin Davidson I reserve the right to fantasize. Whether or not you wish to share my fantasy is entirely up to you.