Finding common values within two sets of delimited numbers in MySQL
The basic problem is that I'm wanting to find the number of values in common between two sets of numbers in MySQL.

Given two fields, each containing a different set of comma-delimited numbers (which could contain up to 100 elements each), using MySQL how can you calculate how many numbers are common to both sets?:

Field 1: 
1,3,75,4502 

Field 2: 
1,10,20,4502,4965,10022

Answer: 2. (1 and 4502 are common to both sets)

The only related function that I can find in MySQL is FIND_IN_SET which lets you know if a single value exists within a set, but it won't work with multiple values. I just wondered if there might be a semi-efficient way to tackle the above problem?
Finding common values within two sets of delimited numbers in MySQL
===

The basic problem is that I'm wanting to find the number of values in common between two sets of numbers in MySQL.

Given two fields, each containing a different set of comma-delimited numbers (which could contain up to 100 elements each), using MySQL how can you calculate how many numbers are common to both sets?:

Field 1: 
1,3,75,4502 

Field 2: 
1,10,20,4502,4965,10022

Answer: 2. (1 and 4502 are common to both sets)

The only related function that I can find in MySQL is FIND_IN_SET which lets you know if a single value exists within a set, but it won't work with multiple values. I just wondered if there might be a semi-efficient way to tackle the above problem?