sqlzoo ´ð°¸È«¼¯

sqlzoo¹ÙÍø

1. SELECT basics ´ð°¸
2. SELECT from world ´ð°¸
3. SELECT from nobel ´ð°¸ todo
4. SELECT in SELECT ´ð°¸ todo
5. SUM and COUNT ´ð°¸
6. JOIN ´ð°¸
7. More JOIN ´ð°¸
8. Using NULL ´ð°¸
   Ö÷ÒªÊÇѧϰ NULLÏà¹ØµÄÄÚÈÝ, INNER JOIN, LEFT JOIN, RIGHT JOIN
9. Self JOIN ´ð°¸ todo