SELECT REVERSE('19,31,1,');
select REVERSE(SUBSTRING_INDEX('19,3,1,',',',1));
select REVERSE(SUBSTRING_INDEX(REVERSE(SUBSTRING_INDEX('19,31,1,',',',2)),',',1));
SELECT SUBSTRING_INDEX('www.mysql.com.aaa', '.', 2);
select REVERSE(SUBSTRING_INDEX('19,3,1,',',',1));
select REVERSE(SUBSTRING_INDEX(REVERSE(SUBSTRING_INDEX('19,31,1,',',',2)),',',1));
SELECT SUBSTRING_INDEX('www.mysql.com.aaa', '.', 2);