SUBSTRING_INDEX¶

SUBSTRING_INDEX(str, delimiter_str, n)

Returns a substring of the input string, which contains all characters that occur before n occurrences of the delimiter string. if n is negative, it will return all characters that occur after the last n occurrences of the delimiter string. If num_occurrences is 0, it will return the empty string

For example:

SUBSTRING_INDEX('1,2,3,4,5', ',', 2) =='1,2'
SUBSTRING_INDEX('1,2,3,4,5', ',', -2) =='4,5'
SUBSTRING_INDEX('1,2,3,4,5', ',', 0) ==''