How to pull out and split the string ID - shek from the database?

Question

MySQL

Here are my categories, in each category, I write down the ID of the post that belongs to this category, how now to pull out all the IDs separately and pull out all the posts by them?

Answer 1

keywords:

• relational database
  
• data normalization
  
• normal forms
  

Answer 2

Bring base to normal form and use JOIN.