【lc-database】181. 超过经理收入的员工

Employee 表包含所有员工，他们的经理也属于员工。每个员工都有一个 Id，此外还有一列对应员工的经理的 Id。

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| Id | Name | Salary | ManagerId |

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| 1 | Joe | 70000 | 3 |

| 2 | Henry | 80000 | 4 |

| 3 | Sam | 60000 | NULL |

| 4 | Max | 90000 | NULL |

±—±------±-------±----------+

给定 Employee 表，编写一个 SQL 查询，该查询可以获取收入超过他们经理的员工的姓名。在上面的表格中，Joe 是唯一一个收入超过他的经理的员工。

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| Employee |

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| Joe |

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1.使用where + 内连接

select * from employee as a,employee b;//笛卡尔积

select * from employee as a,employee b where a.managerId =  b.id and a.salary > b.salary;//筛选条件

select a.name as Employee from employee as a,employee b where a.managerId =  b.id and a.salary > b.salary;

2.join on + 内连接

select  a.name as Employee from employee as a join employee b on a.managerId = b.id  and a.salary > b.salary;