delimiter //

DROP TABLE IF EXISTS /*table-prefix*/breakchar//
CREATE TABLE /*table-prefix*/breakchar (
	c VARCHAR(1)
	) ENGINE=InnoDB//
INSERT INTO /*table-prefix*/breakchar VALUES (' '),('.'),(';'),(','),('-'),('_'),('('),(')'),('/'),('\\')//

DROP TABLE IF EXISTS keyword_query//
CREATE TABLE keyword_query(location INT, querygroup INT, word VARCHAR(64))//

DROP PROCEDURE IF EXISTS /*table-prefix*/parse_query_natural//
CREATE PROCEDURE /*table-prefix*/parse_query_natural (query TEXT)
	LANGUAGE SQL
	DETERMINISTIC
	MODIFIES SQL DATA
	SQL SECURITY INVOKER
	COMMENT 'Parses a natural-language query into a table.'
	BEGIN
		DECLARE i INT DEFAULT 0;
		DECLARE in_quote INT DEFAULT 0;
		DECLARE word VARCHAR(64) DEFAULT '';
		DECLARE location INT DEFAULT 1;
		DECLARE querygroup INT DEFAULT 1;

		each_letter: WHILE i < LENGTH(query) DO BEGIN
			DECLARE curchar VARCHAR(1);
			DECLARE breakchar VARCHAR(1);
			DECLARE done INT DEFAULT 0;
			DECLARE breakchar_cursor CURSOR FOR SELECT c FROM /*table-prefix*/breakchar;
			DECLARE CONTINUE HANDLER FOR SQLSTATE '02000' SET done = 1;

			SET i = i + 1;

			SET curchar = SUBSTRING(query,i,1);

			SELECT curchar;

			IF curchar = '"' THEN BEGIN
				IF in_quote = 0 THEN
					SET in_quote = 1;
				ELSE
					SET in_quote = 0;
				END IF;

				ITERATE each_letter;
			END; END IF;

			OPEN breakchar_cursor;

			LOOP
				FETCH breakchar_cursor INTO breakchar;

				IF done = 1 THEN BEGIN /* not a break character */
					CLOSE breakchar_cursor;

					SET word = CONCAT(word,curchar);

					ITERATE each_letter;
				END; END IF;

				IF curchar = breakchar THEN BEGIN
					CLOSE breakchar_cursor;

					IF LENGTH(word) > 0 THEN BEGIN
						INSERT INTO /*table-prefix*/keyword_query SET location=location,querygroup=querygroup,word=word;
					
						SET word = '';
						SET location = location + 1;
						IF in_quote = 0 THEN SET querygroup = querygroup + 1; END IF;
					END; END IF;

					ITERATE each_letter;
				END; END IF;
			END LOOP;

		END; END WHILE;
	END//

CALL parse_query_natural('foo bar')//