SQL Select Distinct列和最新日期 [英] SQL Select Distinct column and latest date

问题描述

我希望仅根据日期选择表的最新记录，但每个网址仅列出一个。表格结构如下；

I'm looking to select just the latest records of a table based on date, but only one one Distinct listing of each of the urls. The table structure is like this;

ID        URL          DateVisited
1         google.com   01-01-2016
2         yahoo.com    01-02-2016
3         google.com   12-30-2015
4         google.com   02-01-2016

所以对于我的结果集，我想要

So for my result set I would want

google.com     02-01-2016
yahoo.com      01-02-2016

我将有一个在我的实际查询中添加了更多条件，但只想获取命中日志中的最新记录，而不是唯一的URL和日期列表，只是唯一的URL和最新日期。

I will have a couple more conditionals in my actual query, but just want to get the single latest records in a hit log, rather than list of distinct urls and dates, just distinct url's and the latest date.

推荐答案

使用简单的聚合实际上很容易做到，就像这样：

This is actually pretty easy to do using simple aggregation, like so:

select URL, max(DateVisited)
from <table>
group by URL

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