Question

如何从包含三列的表中找到第二高薪，这些列是 id ， name ， {{1 } 但在 salary 中使用。通过 SELF JOIN 进行回答。但是，我想知道如何使用 nested query

进行框架处理

Answer 1

为什么只能使用SELECT语句进行连接？

试试这个：

SELECT DISTINCT salary FROM myTable ORDER BY salary DESC LIMIT 1,1 ;

Answer 2

如果你必须使用自我加入，你可以做这样的事情......

SELECT x.val 
  FROM my_table x 
  JOIN my_table y 
    ON y.val >= x.val 
 GROUP 
    BY x.val HAVING COUNT(DISTINCT y.val) = ?

Answer 3

从包含三个颜色ID，名称，工资的表中查找第二高薪：

SELECT id,NAME,salary FROM high
WHERE salary = (SELECT DISTINCT(salary) FROM high AS e1
WHERE (SELECT COUNT(DISTINCT(salary))=2 FROM high AS e2
WHERE e1.salary <=e2.salary))
ORDER BY NAME;

查看sqlfiddle

anthor一个有趣的答案：

SELECT id,NAME,salary
FROM high 
WHERE salary = (SELECT DISTINCT(salary) 
                FROM high AS e1 
                WHERE id  = (SELECT COUNT(DISTINCT(salary)) 
                             FROM high AS e2 
                             WHERE e1.salary <= e2.salary))

从包含三列Id，名称，工资的表中查找第二高薪

3 个答案: