PHP怎么按日期查询

PHP如何按日期查询
MYSQL里字段addtime为时间戳
我现在须要这样查询
xx.php?u=20130328&page=1 &page=这个用来分页
 这样查询20130328或20130329这一天数据

<?php<br />
include "../include/song.inc.php";<br />
$key = $_GET['u'];<br />
if($_GET["page"]){<br />
    $page=$_GET["page"];#获取要显示的页码<br />
}else{<br />
    $page=1;#没有参数传入时，显示第一页<br />
}<br />
$col=20;#每页显示记录条数<br />
$p=($page-1)*$col;<br />
$runSql = mysql_query("select * from cmsdj_song where uid = '$key' order by id desc limit ".$p.",".$col."");<br />
while($row = mysql_fetch_array($runSql))<br />
{<br />
//下面这些是调用值<br />
$sid=$row['id'];<br />
$suid=$row['uid'];<br />
$supip=$row['upip'];<br />
$name=$row['name'];<br />
$sname=substr($name,0,30);<br />
$sfile=$row['file'];<br />
$surl=$row['url'];<br />
$swjdx=$row['wjdx'];<br />
$stime=date('Y-m-d H:i:s',$row['addtime']);<br />
//$b64file=base64_encode($surl);<br />
?><br />
<table width='100%' border='0' cellpadding='0' cellspacing='0' class='tb_style'><br />
<tr><br />
<center><br />
<td width='5%' height='20' class='td_border'> <? echo $sid;?></td><br />
<td width='25%' class='td_border'><a href='u.php?i=<? echo $sfile;?>'> <? echo $sname;?></a></td><br />
<td width='20%' class='td_border'><a href='u.php?i=<? echo $sfile;?>'><? echo $sfile;?></a></td><br />
<td width='20%' class='td_border'><a href='u.php?i=<? echo $sfile;?>'><? echo $surl;?></a></td><br />
<td width='5%' class='td_border' align='center'><? echo $swjdx;?></td><br />
<td width='10%' class='td_border' align='center'><? echo $supip;?></td><br />
<td width='12%' class='td_border' align='center'><? echo $stime;?></td><br />
<td width='3%' class='td_border' align='center'><a href='del.php?id=<? echo $sid;?>'><img  src='/img/no.gif' border='0' alt=" PHP怎么按日期查询 " ></a></td><br />
</tr><br />
</center><br />
</table><br />
<?php<br />
}<br />
?>     <br />
<?php<br />
$col=20;#每页显示记录条数<br />
$count=mysql_query("select id from cmsdj_song where uid like '%$key%'");#取得记录总条数<br />
$num = mysql_num_rows($count)/$col;#计算页数<br />
$nnx = mysql_num_rows($count);#计算页数<br />
$num=ceil($num);#无条件小数进位确定总页数<br />
mysql_close();<br />
?>

------解决方案--------------------
FROM_UNIXTIME()  UNIX时间戳转换为日期
UNIX_TIMESTAMP() 日期转换为UNIX时间戳 
------解决方案--------------------

<br />
$u = $_GET['u'];<br />
<br />
$starttime = strtotime($u.'000000');<br />
$endtime =  strtotime($u.'235959');<br />
<br />
$runSql = mysql_query("select * from cmsdj_song where addtime > '$starttime' and addtime<'$endtime' order by id desc limit ".$p.",".$col."");<br />