How to count how many specific characters are in a string using SQL?

Question

MySQL

There is an array with commas, I store it in the database, how to calculate how many people are employed there?
Subsequently, I will need to display the values ​​​​where more, let's say 5 busy.

Answer 1

replace all commas with an empty string and calculate the difference in string lengths

Answer 2

select len('test, with, commas,,,') - len(REPLACE('test, with, commas,,,', ',', ''))