MySQL specific adventure about table creation

crazyQuery.sql

-- RUN ONLY ONCE TO DEPLOY PROCEDURE & FUNCTION INTO DB
DELIMITER $$

-- FUNCTION TAKES STRING, DELIMITER AND POSITION
-- AND RETURNS SUBSTRING OF DEFINED POSITION BY DELIMITERS
-- IF DELIMITER NOT FOUND OR OUT OF RANGE WILL RETURN '' (empty string)
-- Example: SPLIT_STR('ABRA / SCHWABRA / KADABRA',' / ',3) returns 'KADABRA'
--
-- IF DELIMITER NOT FOUND OR OUT OF RANGE WILL RETURN '' (empty string)
-- Example: SPLIT_STR('-/-',',',1) returns ''
-- EXample: SPLIT_STR('1,2,3',',',5) returns ''

CREATE FUNCTION SPLIT_STR(x VARCHAR(65432), delim VARCHAR(5), pos INT)
  RETURNS VARCHAR(65432) DETERMINISTIC
BEGIN 
    RETURN REPLACE(SUBSTRING(SUBSTRING_INDEX(x, delim, pos),
       LENGTH(SUBSTRING_INDEX(x, delim, pos -1)) + 1),
       delim, '');
END$$

-- PROCEDURE TAKES str STRING AND SPLITS IT BY delim INTO TEMP TABLE
-- whie saving value converts it to INT
CREATE PROCEDURE FILT3R(str VARCHAR(65432), delim VARCHAR(5)) 
BEGIN 
  SET @x = 1; 
  DROP TEMPORARY TABLE IF EXISTS filt3r;
  CREATE TEMPORARY TABLE filt3r(id int) ENGINE=Memory; 
  REPEAT 
    SET @id = (SELECT CAST(SPLIT_STR(str,delim,@x) AS UNSIGNED));
    INSERT INTO filt3r SET id=@id; 
    SET @x = @x + 1; 
  UNTIL SPLIT_STR(str,delim,@x) = '' END REPEAT; 
END$$

DELIMITER ;
-- RUN ONCE ENDS HERE 


-- USAGE
CALL FILT3R('1,2,3,5,6',','); -- this will populate temporary table filt3r with values
SELECT id FROM filt3r WHERE id not in ( <INSERT_YOUR_QUERY_HERE> )