kristok/node-pgq

create or replace function pgq.seq_getval(i_seq_name text)
returns bigint as $$
-- ----------------------------------------------------------------------
-- Function: pgq.seq_getval(1)
--
--      Read current last_val from seq, without affecting it.
--
-- Parameters:
--      i_seq_name     - Name of the sequence
--
-- Returns:
--      last value.
-- ----------------------------------------------------------------------
declare
    res     int8;
    fqname  text;
    pos     integer;
    s       text;
    n       text;
begin
    pos := position('.' in i_seq_name);
    if pos > 0 then
        s := substring(i_seq_name for pos - 1);
        n := substring(i_seq_name from pos + 1);
    else
        s := 'public';
        n := i_seq_name;
    end if;
    fqname := quote_ident(s) || '.' || quote_ident(n);

    execute 'select last_value from ' || fqname into res;
    return res;
end;
$$ language plpgsql strict;

create or replace function pgq.seq_setval(i_seq_name text, i_new_value int8)
returns bigint as $$
-- ----------------------------------------------------------------------
-- Function: pgq.seq_setval(2)
--
--      Like setval() but does not allow going back.
--
-- Parameters:
--      i_seq_name      - Name of the sequence
--      i_new_value     - new value
--
-- Returns:
--      current last value.
-- ----------------------------------------------------------------------
declare
    res     int8;
    fqname  text;
begin
    fqname := pgq.quote_fqname(i_seq_name);

    res := pgq.seq_getval(i_seq_name);
    if res < i_new_value then
        perform setval(fqname, i_new_value);
        return i_new_value;
    end if;
    return res;
end;
$$ language plpgsql strict;