SQL通过一列选择唯一值，而在另一列中选择最新值

Question

我具有以下表格结构：

leads:

name  | email | date
-------------------------------------------------------
John  | [email protected]  | 2020-01-21
J     | [email protected]  | 2020-01-20
Alex  | [email protected]  | 2020-01-19
A     | [email protected]  | 2020-01-18
James | [email protected] | 2020-01-17

我只需要选择带有UNIQUE电子邮件和最新关联名称的行，这样预期的结果是：

name  | email | date
-------------------------------------------------------
John  | [email protected]  | 2020-01-21
Alex  | [email protected]  | 2020-01-19
James | [email protected] | 2020-01-17

Answer 1

不存在使用

select * from tbl a 
where not exist(select 1 from tbl b where a.email = b.email  and a.date < b.date)