Tricks to use LIMIT clause within subquery

Well, I try to use LIMIT clause in my subquery. It doesn't work with MySQL 5, and the error message states that: This version of MySQL doesn't yet support 'LIMIT & IN/ALL/ANY/SOME subquery'. Here is my first query:

SELECT * FROM user_activities WHERE DATE(activity_date)
IN (
SELECT
DISTINCT DATE(activity_date)
FROM user_activities
WHERE
user_id = 1069
ORDER BY
activity_date
DESC
LIMIT 3)

So, I ask my friend dara and a code from the Internet. His idea and that code is quite similar. The trick is to use a join statement. Make the subquery that use limit clause join with the original table. Here is my second code, it works:

SELECT ua.* FROM (SELECT DISTINCT DATE(activity_date) AS activity_date FROM user_activities WHERE user_id = 1069 ORDER BY activity_date DESC LIMIT 3) AS A INNER JOIN user_activities as ua ON DATE(ua.activity_date) = DATE(A.activity_date) WHERE ua.user_id = 1069 ORDER BY ua.activity_date DESC

Disable text selection on IE and FF

Last time, I posted a javascript function that disable text selection on IE and FF. This post doesn't need javascript to achieve this problem.

On FF, set -moz-user-select to none.

On IE, set attribute onselectstart to return false.

Here is an example:

<div onselectstart="return false;" style="-moz-user-select: none;">
 <p>Bibology for all.</p>
 <p>All for Kibology.</p>
</div>

Fixing position: fixed on IE6

Maybe some of you realizes that IE6 doesn't support position: fixed because of its bug. Luckily, there is another bug works in a way that ALLOWS this to be done! Here is the solution besides using javascript to move the element when the user is scrolling:

1. First, put IE6 into "standards mode" by using a strict DOCTYPE.

2. Use IE conditional comments to style the HTML and BODY tags like so:

html, body { height: 100%; overflow: auto; }

3. Style anything you want to stay fixed as position:absolute.

#menu {
position: fixed;
top: 100px;
left: 100px;
border: 1px solid #ccc;
}
* html #menu {
position: absolute; /* IE */
}

4. The only problem with this is that you cannot use absolute or relative positions on the moving page but float is allowed.

jYMSG - Yahoo! Instant Messenger Library for Java

I just founded and tested a java library called jYMSG that provides a way for Java applications to connect and use the Yahoo Instant Messenger protocol, version 10 (YMSG-10) in a reasonably coder friendly and abstract way.

It is very nice. Here are serveral link about yahoo messenger protocol:

http://en.wikipedia.org/wiki/YMSG
http://jymsg9.sourceforge.net/