Please help on MS SQL Procedure (@@rowcount) translate to Postgresql Function

I have some MS SQL Store Procedure code as following:

update ot_ValReq
set delete_ind = 'Y'
where val_req_no in (@p_keys)

if @@rowcount = 0
begin
select @i_return = 3
goto error_handler
end

1. How can I get @@rowcount in postgresql or have any other method to check?
2. Can goto statement use in postgresql?

Thanks a lot.