Description:
substring_index() returns the part of a string from the beginning to nth delimiter of from nth delimiter to the end, but sometimes it is needed to get just a nth part of a string, using a delimiter. For ex., when dealing with IPs, it would be convenient to extract any of the 4 parts of them using a call like
substring_part(IP, N, '.')
where N=1..4
How to repeat:
Of course, the same can be done with substring_index() called twice and sometimes locate() but that is more complicated and inconvenient. Getting a part of a string is not the only task - one may need to know its length or add it to a longer expression, and having to deal with more complicated formulas to just get a part of a string and then to repeat it multiple times across the whole query makes the query look too big and messy.
Suggested fix:
I think this is a very simple feature to implement.
There's a language (M) that has it as its primary way of dealing with data: all data is stored/read/written using a delimiter (chr(22)).
