Re: String manipulation

pativo(at)arcor(dot)de (pativo) wrote in message news:<58babf1b(dot)0402170346(dot)4a719868(at)posting(dot)google(dot)com>...

Hello and thanks to all!

I'm amused that I get so many responses.

Ok, at time I use a plpgsql function (isAHex(VARCHAR)) which checks only
if the length is even.
So I think I should implement the following.

=======8<-------------------------------------------------------------------

CREATE FUNCTION isAHex(VARCHAR) RETURNS BOOLEAN AS '
DECLARE
input_text_p ALIAS FOR $1;
tmp_char VARCHAR;
BEGIN
IF ((length(input_text_p) % 2) <> 0) THEN
RETURN FALSE;
END IF;
FOR i IN 1..length(input_text_p) LOOP
tmp_char := substr(input_text_p, i, 1);
IF NOT tmp_char ~ ''[0-9a-fA-F]'' THEN
RETURN FALSE;
END IF;
END LOOP;
RETURN TRUE;
END;
' LANGUAGE 'plpgsql';

CREATE TABLE textsTest (
surrogate VARCHAR(40) PRIMARY KEY,
hex_text VARCHAR(150) NOT NULL CHECK(isAHexTest(hex_text))
);

=======8<-------------------------------------------------------------------

But for next release I will use the following. This is in my eyes
the better solution.

=======8<-------------------------------------------------------------------

CREATE TABLE textsTest (
surrogate VARCHAR(40) PRIMARY KEY,
hex_text TEXT NOT NULL CHECK(text ~ '^([0-9A-Fa-f]{2})+$')
);

=======8<-------------------------------------------------------------------

Thanks to all!!!

oki,

pativo

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