摘要：
select if(count(salary) = 0, NULL, salary) as `salary` from (select salary from Employee group by salary order by salary desc limit 1,1) tmpWrite a S... 阅读全文
摘要：
SELECT FirstName, LastName, City, State FROM Person pLEFT JOIN Address a ON p.PersonId = a.PersonId居然出SQL的题目了，左连接就行 阅读全文
摘要：
class BSTIterator {private: TreeNode* current; stack nodeStack;public: BSTIterator(TreeNode *root) { current = root; } /** @retu... 阅读全文