Aggregate functions GROUP BY

1. SELECT title, author_lname FROM books;
2.  
3. SELECT title, author_lname FROM books
4. GROUP BY author_lname;
5.  
6. SELECT author_lname, COUNT(*)
7. FROM books GROUP BY author_lname;
8.  
9.  
10. SELECT title, author_fname, author_lname FROM books;
11.  
12. SELECT title, author_fname, author_lname FROM books GROUP BY author_lname;
13.  
14. SELECT author_fname, author_lname, COUNT(*) FROM books GROUP BY author_lname;
15.  
16. SELECT author_fname, author_lname, COUNT(*) FROM books GROUP BY author_lname, author_fname;
17.  
18. SELECT released_year FROM books;
19.  
20. SELECT released_year, COUNT(*) FROM books GROUP BY released_year;
21.  
22. SELECT CONCAT('In ', released_year, ' ', COUNT(*), ' book(s) released') AS year FROM books GROUP BY released_year;