从列中选择唯一值 [英] selecting unique values from a column

问题描述

我有一个MySQL表，其中包含以下类型的信息:

I have a MySQL table which contains the following type of information:

    Date            product 
2011-12-12           azd
2011-12-12           yxm
2011-12-10           sdx
2011-12-10           ssdd  

这是我用来从该表中获取数据的脚本示例:

Here is an example of a script I use to get data from this table:

<?php

$con = mysql_connect("localhost","username","password");
if (!$con)
  {
  die('Could not connect: ' . mysql_error());
  }
mysql_select_db("db", $con);
$sql=mysql_query("SELECT * FROM buy ORDER BY Date");
while($row = mysql_fetch_array($sql))
{

 echo "<li><a href='http://www.website/". $row['Date'].".html'>buy ". date("j, M Y", strtotime($row["Date"]))."</a></li>";

    }
    mysql_close($con);
?> 

此脚本显示表格中的每个日期，例如

This script displays every date from the table, e.g.

12.dec 2011
12.dec.2011
10.dec.2011
10.dec.2011

我只想显示唯一的日期，例如

I would like to only display unique dates, e.g.

12.dec.2011
10.dec.2011

推荐答案

使用 DISTINCT 在MySQL中的运算符:

Use the DISTINCT operator in MySQL:

SELECT DISTINCT(Date) AS Date FROM buy ORDER BY Date DESC;

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