Re: IsDate function in plpgsql

[Bricklen Anderson <banderson(at)presinet(dot)com>]

Sistemas C.M.P. wrote:
> A few days ago, someone in this list gives  me a function (plpgsql) that 
> evaluates if a string is a valid date or not.
> It returns 1 or 0 (valid/Not Valid)
> The problem is that if the argument is a NULL field the function returns 1.
> I don't have experience with plpgsql language.
> This is the function
>  
> begin

>   perform $1::date;
>   return 1;
> exception when others then
>   return 0;
> end

create or replace function datetest (text) returns integer as $$
begin
    if ($1 is null) then
        return 0;
    end if;
    perform $1::date;
    return 1;
exception when others then
    return 0;
end;
$$ language plpgsql;