从mysql表中提取唯一值，并按出现次数排序

Question

I'm having a little trouble with this, I found how to get unique values from multiple columns, and I know how to sort normally, but I can't seem to mix the two

The original sql statement is here:

$sql="SELECT DISTINCT UserID, UserIP FROM Visits WHERE PageID='".$_GET['p']."'";

It only gets the first instance of where both values are unique, so doing the 'mysql_numrows' thing doesn't work.

This is from within the fetch array loop, it can count the occurrences fine, but at that point it's a bit too late to sort

$sql5="SELECT Date, VisitID FROM Visits WHERE PageID='".$_GET['p']."' AND UserID='".$userid."' AND UserIP='".$userip."' ORDER BY Date";
$result5 = mysql_query($sql5);
$num5 = mysql_numrows($result5);

Basically, it should get unique values based on both columns, count how many times the appear, sort by count, then potentially also sort by the highest matching date if possible

Any suggestions would be great, cheers :)
Also it's just for a personal site, I'm not actually doing anything with the info, just trying to learn some more php

Answer 1

Try using GROUP BY, like this:

SELECT UserID, UserIP FROM Visits 
WHERE PageID = ###
GROUP BY UserID, UserIP
ORDER BY COUNT(*) DESC, max(`Date`) DESC