Re: [GENERAL] easy task: concurrent select-updates

[Nickolay]

Kevin McConnell wrote:
CREATE OR REPLACE FUNCTION public.getmsg() RETURNS integer LANGUAGE plpgsql
AS $function$
declare
      rec record;
begin
      for rec in select id from msg where busy =alse order by id loop
              update msg set busy =rue where id = rec.id and busy = false;
              if found then
                      return rec.id;
              end if;
      end loop;
      return -1;
end;
$function$
    

I think you could also do something roughly similar in a statement by
using a RETURNING clause on the update, such as:

  update msg set busy =rue where id = (select min(id) from msg where
busy =alse) returning *;

Cheers,
Kevin
  

Thank you guys! But what's min(id) for? Is it neccessary? Is there any 
chance I can replace min(id) to LIMIT 1?

Best regards, Nick.

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