Various useful MySQL string functions. (Original source: http://goo.gl/udse6R)

split_delmited_string.sql

CREATE FUNCTION strSplit(x varchar(255), delim varchar(12), pos int) returns varchar(255)
return replace(substring(substring_index(x, delim, pos), length(substring_index(x, delim, pos - 1)) + 1), delim, '');

select strSplit("aaa,b,cc,d", ',', 2) as second;
+--------+
| second |
+--------+
| b |
+--------+

select strSplit("a|bb|ccc|dd", '|', 3) as third;
+-------+
| third |
+-------+
| ccc |
+-------+

select strSplit("aaa,b,cc,d", ',', 7) as 7th;
+------+
| 7th |
+------+
| NULL |
+------+