url_encode_utf8.sql

DELIMITER $$

DROP FUNCTION IF EXISTS `url_encode` $$
CREATE DEFINER=`root`@`%` FUNCTION `url_encode`(original_text text) RETURNS text CHARSET utf8
BEGIN
	declare new_text text DEFAULT NULL;
	declare current_char varchar(10) DEFAULT '';
	declare ascii_current_char int DEFAULT 0;
	declare pointer int DEFAULT 1;
	declare hex_pointer int DEFAULT 1;
	
	IF original_text IS NOT NULL then
		SET new_text = '';
		while pointer <= char_length(original_text) do
			SET current_char = mid(original_text,pointer,1);
			SET ascii_current_char = ascii(current_char);
			IF current_char = ' ' then
				SET current_char = '+';
			ELSEIF NOT (ascii_current_char BETWEEN 48 AND 57 || ascii_current_char BETWEEN 65 AND 90 || ascii_current_char BETWEEN 97 AND 122
									 || ascii_current_char = 45 || ascii_current_char = 95 || ascii_current_char = 46 || ascii_current_char = 126
									 || ascii_current_char = 34
									) then
				SET current_char = hex(current_char);
				SET hex_pointer = char_length(current_char)-1;
				while hex_pointer > 0 do
					SET current_char = INSERT(current_char, hex_pointer, 0, "%");
					SET hex_pointer = hex_pointer - 2;
				end while;
			end IF;
			SET new_text = concat(new_text,current_char);
			SET pointer = pointer + 1;
		end while;
	end IF;
	
	RETURN new_text;
END $$

DELIMITER ;