Dynamic PL/pgSQL select query: value association propblem - Mailing list pgsql-general

From Thiemo Kellner
Subject Dynamic PL/pgSQL select query: value association propblem
Date
Msg-id 20180216132049.76333zk3lgrasquc@www.gelassene-pferde.biz
Whole thread Raw
Responses Re: Dynamic PL/pgSQL select query: value association propblem  (Pavel Stehule <pavel.stehule@gmail.com>)
RE: Dynamic PL/pgSQL select query: value association propblem  (Igor Neyman <ineyman@perceptron.com>)
List pgsql-general
Hi all

I would like to have a generic trigger function that compares on
insert if there is already a record in the table with the very same
values. Using PL/pgSQL ( I am not bound to that) I know the insert
record structure from the new record and I can build a select query
dynamically from the catalogue, but I do not know to associate the new
record values to the corresponding columns. An example
Table T has columns Q and L, in that order. If I create an insert
trigger function I have the new values in new.L and new.Q. From the
catalogue I can create a the select query S_QUERY:
select count(*) > 0 from T where A = $1 and B = $2. But when I want to
EXECUTE S_QUERY USING it fails because I cannot use something like
NEW[1].

Is there a way to convert the record type into an array type? Or is
there even a way to do it more directly like WHERE T.RECORD = NEW?

Kind regards Thiemo

--
Öffentlicher PGP-Schlüssel:
http://pgp.mit.edu/pks/lookup?op=get&search=0x8F70EFD2D972CBEF

----------------------------------------------------------------
This message was sent using IMP, the Internet Messaging Program.


pgsql-general by date:

Previous
From: Michael Krüger
Date:
Subject: Re: Parallel Query - Can it be used within functions?
Next
From: mariusz
Date:
Subject: strange construct with RETURN within plpgsql