Re: Regular expression in an if-statement will not work

On 9 September 2010 12:55, Ungermann Carsten <
carsten(dot)ungermann(at)ib-ungermann(dot)de> wrote:

> Dear postgres list,
>
> I need to verify the value of a column by a regular expression in an
> if-statement before insert or update. It should be a one to three digit
> value. I wrote a trigger and a trigger function. In the trigger function I
> want to use the following if-statement to verify the value:
>
> IF new.value !~ E'^\d{1,3}$' THEN RAISE EXCEPTION '...some text...'; END
> IF;
>
> It will not work! Why?
>
>
How about this:

IF new.value !~ E'^\\d{1,3}$' THEN

Or if you only want to check the 3digit value, without any trigger, IMHO
this is much simpler:

alter table x add constraint check_is_3_digit check ( value ~ E'^\\d{3}$' );

regards
Szymon Guz