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

[Ungermann Carsten <carsten.ungermann@xxxxxxxxxxxxxxx>]

I tried it once more, now. There is no change in the behavior. I use the $$-notation to avoid double "\" and double "'". Also there is no syntax error in this statement.

The constraint is a bad option because I have to log errors when I import a csv-file.

Thanks and regards

Carsten Ungermann

Am 09.09.2010 um 15:44 schrieb Szymon Guz:

On 9 September 2010 12:55, Ungermann Carsten <carsten.ungermann@xxxxxxxxxxxxxxx> 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