MySQL查詢和PHP代碼

Question

我有用於顯示2個表tbl_category

id category 
1 cat1 
2 cat2 
3 cat3 

和第二表Tbl_book

id cat_id book_name 
1 1  book1 
2 1  book2 
3 2  book4 
4 1  book5 

MySQL查詢和PHP代碼

cat1 book1 book2 book5 
cat2 book4 

Answer 1

怎麼樣

select c.category, 
     group_concat(b.bookname separator ' ') as books 
from tbl_category c 
inner join tbl_book b on b.cat_id = c.id 
group by c.category