Dynamic PL/pgSQL select query: value association propblem

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

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