mysql自定函數分割字串

https://gist.github.com/ntomka/fbf8e8b48690cecafe39

CREATE FUNCTION SPLIT_STRING(str VARCHAR(255), delim VARCHAR(12), pos INT) 
RETURNS VARCHAR(255) 
DETERMINISTIC 
RETURN REPLACE(SUBSTRING(SUBSTRING_INDEX(str, delim, pos),
        LENGTH(SUBSTRING_INDEX(str, delim, pos-1)) + 1),
        delim, '');

用法和內建的function一樣。例如下例會顯示pear。

SELECT SPLIT_STRING('apple, pear, melon', ',', 2)