mysql训练题网站
SELECT MAX(Salary) AS SecondHighestSalary FROM Employee WHERE Salary
HackerRank是一个提供计算机编程技能评测的平台。它的关系型数据库练习分类中有很多MySQL训练题，适用于不同水平的开发人员，从初学者到专业人士。以下是一个示例题目：
SELECT City, CountryCode, Population FROM City WHERE population >100000 AND CountryCode = 'USA' ORDER BY Population DESC;
