MySQL to create stored procedure and function to update duplicate URL keys to be unique

duplicate_keys.sql

DELIMITER ;;
CREATE DEFINER=`magento_prod`@`%` FUNCTION `generate_unique_url_key`(target_value_id INT) RETURNS LONGTEXT CHARSET latin1
    READS SQL DATA
BEGIN
	DECLARE url_key_attr_id INT DEFAULT 124;
	DECLARE counter INT DEFAULT 1;
	DECLARE url_key LONGTEXT;
	DECLARE first_pass BOOLEAN DEFAULT TRUE;
	# Retrieve current URL key for provided value_id row
	SELECT `VALUE` INTO @current_url_key FROM catalog_product_entity_varchar WHERE value_id = target_value_id;
	SET @new_url_key = @current_url_key;
	SELECT count(*) INTO @url_count FROM catalog_product_entity_varchar WHERE attribute_id = url_key_attr_id AND `VALUE` = @new_url_key;
	WHILE @url_count > 1 DO
		# There is more than one occurrence of URL key
		IF first_pass IS TRUE
		THEN
			# Count number of hyphens in URL
			SELECT LENGTH(@current_url_key) - LENGTH(REPLACE(@current_url_key, '-', '')) INTO @hyphen_count;
			IF @hyphen_count > 0
			THEN
				# Extract the right-most section of the URL key
				SELECT SUBSTRING_INDEX(@current_url_key, '-', -1) INTO @tail_section;
			ELSE
				SET @tail_section = NULL;
			END IF;
			IF @tail_section REGEXP '^-?[0-9]+$'
			THEN
				# This key appears to already have an appended hyphen and increment number, remove it before proceeding
				SET @current_url_key = SUBSTRING(@current_url_key, 1, (LENGTH(@current_url_key) - (LENGTH(@tail_section) + 1)));
			END IF;
			# No longer the first pass
			SET first_pass = FALSE;
		END IF;
		# Append hyphen and counter
		SET @new_url_key = concat(@current_url_key, '-', counter);
		# Increase counter for next run through
		SET counter = counter + 1;
		# Check for other instances of this key
		SELECT count(*) INTO @url_count FROM catalog_product_entity_varchar WHERE attribute_id = url_key_attr_id AND `VALUE` = @new_url_key;
		# Add one, because we will have one more instance if we use this key
		SET @url_count = @url_count + 1;
	END WHILE;	
	RETURN @new_url_key;
END;;
DELIMITER ;

DELIMITER $$
# Procedure to replace duplicate URL keys with unqiue ones
CREATE PROCEDURE update_duplicate_url_keys() MODIFIES SQL DATA
BEGIN
  DECLARE url_key_attr_id INT DEFAULT 124;
  DECLARE cursor_value_id INT;
  DECLARE done INT DEFAULT FALSE;
  # Define cursor to retrieve list of duplicate value IDs
  DECLARE cursor_i CURSOR FOR SELECT value_id FROM catalog_product_entity_varchar WHERE attribute_id = url_key_attr_id and `value` IN (SELECT DISTINCT `VALUE` FROM catalog_product_entity_varchar WHERE attribute_id = url_key_attr_id GROUP BY `VALUE` HAVING count(`VALUE`) > 1);
  DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;
  OPEN cursor_i;
  read_loop: LOOP
    FETCH cursor_i INTO cursor_value_id;
    IF done THEN
      LEAVE read_loop;
    END IF;
    # Update offending value ID with a new (unique) URL key value
    UPDATE catalog_product_entity_varchar SET `VALUE` = generate_unique_url_key(cursor_value_id) WHERE value_id = cursor_value_id;
    COMMIT;
  END LOOP;
  CLOSE cursor_i;
END $$
DELIMITER ;