Php-ask a database design question

Recently, I encountered a problem when I was creating a participating file. I designed it like this: add two fields, one is the total number of followers, and the other is the total number of followers, which is easy to understand, the key here is that the attention IDs are separated by commas. for example, if the uid in the ID table is 13579, users are, 9. how can I save and read the data in the method above when adding the attention? how can I remove the comma? Development language PHP database MYSQL framework TP beginner php

Recently I encountered a problem when I was creating a participating file. I needed to make a feature that I designed as follows:
Add two fields
One is the total number of followers
One is the concerned ID

The total number of followers is easy to understand. The key is attention.
Follow IDs are separated by commas. for example, if the uid in the ID table is 1, 3, 5, 7, 9
Is 1, 3, 5, 7, 9

How can I save and read data in the above method when adding the attention? how can I remove the comma?

Development language PHP database MYSQL framework TP

Beginner