利用sql的limit属性对mysql数据库_MySQL

//利用sql的limit属性对mysql数据库
function pagetorecord($page,$pagecounts){
$result=($page-1)*$pagecounts;
return $result;
}

function pagech($page,$j){
if($j==1){
$p=$page+1;}
else{
$p=$page-1;}
return $p;
}

$pagecounts=20;
if($startpage){
$startpage=$startpage;
}
else{
$startpage=1;
}

$sqltr="select * from main order by sm limit ".pagetorecord($startpage,$pagecounts).",".$pagecounts;
$connect=mysql_connect("localhost","http","something");
$select=mysql_select_db('book',$connect);
$query=mysql_query('select count(*) as total from main',$connect);
$totalrecord=mysql_result($query,0,"total");
$query=mysql_query($sqltr,$connect);
//-------------------------------
echo "

";
echo"";
$i=1;
while($array=mysql_fetch_array($query)){
printf("",
$i,$array[bzsh],$array[sm],$array[cbs],$array[dj]);
$i++;
}
echo"

序号	标准书号	书名	出版社	定价
%d	%s	%s	%s	%f

";
echo"

---

";
mysql_close($connect);
if(0==$totalrecord%$pagecounts){
$totalpage=floor($totalrecord/$pagecounts);}
else{
$totalpage=floor($totalrecord/$pagecounts)+1;
}

//echo $sqltr;
if($startpage==1){
if($totalpage>1){
echo"首页 ";
echo"前页 ";
echo "下页 ";
echo "尾页 共".$totalpage."页 第".$startpage."页";
}
else{
echo"首页 ";
echo"前页 ";
echo"下页 ";
echo"尾页 ";
}

}
elseif($startpage==$totalpage){
echo "首页 ";
echo "前页 ";
echo"下页 ";
echo"尾页 共".$totalpage."页 第".$startpage."页";
}
else{
echo "首页 ";
echo "前页 ";
echo "下页 ";
echo "尾页 共".$totalpage."页 第".$startpage."页";
}

?>