[SQL] Variable column names in PL/pgSQL RECORD referencces

[Ken Winter]

(Sorry for the redundancy – I sent this query earlier but forgot to put a title on it.  Seems like it would be more useful with a title, so here it is again.  If there’s a moderator who can delete my earlier message, please do so.)   In PL/pgSQL, is there a way to put a *variable* column-name in a dot notation reference to a RECORD column?   For example, suppose I want to write a function like the following, which is to be called by a "BEFORE INSERT" trigger:   CREATE OR REPLACE FUNCTION foo (  ) RETURNS TRIGGER AS     '     DECLARE         var VARCHAR;     BEGIN         var := TG_ARGV[0]               NEW.<the column whose name is the value of var> := ''whatever'';         RETURN NEW;         END;     '     LANGUAGE 'plpgsql' ;   The aim of this uninteresting function is to assign the value 'whatever' to the table column that is passed in by the calling trigger as TG_ARGV[0], i.e. the first calling argument.    What I don't know is what to put into the dot notation in place of ".<the column whose name is the value of var>" so that the column of NEW that is addressed by the assignment statement is the one passed in as the first argument.  Is there any PL/pgSQL construct that could be substituted in here to achieve this result?   If not, can anybody suggest a way to write a trigger-called function that would accomplish the same result?   In case it's not obvious, the underlying goal is to write a single trigger-called function that could modify different columns for each trigger that called it, where each trigger specified the target column by a calling argument (or by any other viable mechanism).   ~ TIA ~ Ken