Wednesday, February 19, 2020

Aggregate functions COUNT

  1. SELECT COUNT(*) FROM books;
  2.  
  3. SELECT COUNT(author_fname) FROM books;
  4.  
  5. SELECT COUNT(DISTINCT author_fname) FROM books;
  6.  
  7. SELECT COUNT(DISTINCT author_lname) FROM books;
  8.  
  9. SELECT COUNT(DISTINCT author_lname, author_fname) FROM books;
  10.  
  11. SELECT title FROM books WHERE title LIKE '%the%';
  12.  
  13. SELECT COUNT(*) FROM books WHERE title LIKE '%the%';
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