How to Group By This Comma-Delimited Data

I have data like this :

ID  Book    Author
1   Book A  Andy, Brian
2   Book B  Andy, Charlie
3   Book C  Brian

How to group by the data so i can get like this:

Author  Count
开发者_StackOverflow中文版Andy    2
Brian   2
Charlie 1

If we assume you have a normalized structure, you simply need to :

SELECT a.author, count(*) 
FROM books b
INNER JOIN author a ON a.author_id=b.author_id
GROUP BY a.author