分享一些php常用代码（链接数据库，分页）

[php]代码库

1、连接MYSQL数据库代码
<?php
$connec=mysql_connect("localhost","root","root") or die("不能连接数据库服务器： ".mysql_error());
mysql_select_db("liuyanben",$connec) or die ("不能选择数据库: ".mysql_error());
mysql_query("set names 'gbk'");
?>
2、读取数据库，并实现循环输出
<?php
$sql="select * from liuyan order by ly_id desc";
$conn=mysql_query($sql,$connec);
while($rs=mysql_fetch_array($conn)){
?>
循环的内容.........
<?php
}
?>
3、如何实现分页，包括两个函数，两个调用
1）两个函数
<?
//分页函数
function genpage(&$sql,$page_size=2)
{
      global $prepage,$nextpage,$pages,$sums; //out param
      $page = $_GET["page"];
      $eachpage = $page_size;
      $pagesql = strstr($sql," from ");
      $pagesql = "select count(*) as ids ".$pagesql;
      $conn = mysql_query($pagesql) or die(mysql_error());
      if($rs = mysql_fetch_array($conn)) $sums = $rs[0];
      $pages = ceil(($sums-0.5)/$eachpage)-1;
      $pages = $pages>=0?$pages:0;
      $prepage = ($page>0)?$page-1:0;
      $nextpage = ($page<$pages)?$page+1:$pages;
      $startpos = $page*$eachpage;
    $sql .=" limit $startpos,$eachpage ";
}
//显示分页
function showpage()
{
    global $page,$pages,$prepage,$nextpage,$queryString; //param from genpage function
    $shownum =10/2;
    $startpage = ($page>=$shownum)?$page-$shownum:0;
    $endpage = ($page+$shownum<=$pages)?$page+$shownum:$pages;
  
    echo "共".($pages+1)."页: ";
    if($page>0)echo "<a href=$PHP_SELF?page=0$queryString>首页</a>";
    if($startpage>0)
        echo " ... <b><a href=$PHP_SELF?page=".($page-$shownum*2)."$queryString>?</a></b>";
    for($i=$startpage;$i<=$endpage;$i++)
    {
        if($i==$page)    echo " <b>[".($i+1)."]</b> ";
        else        echo " <a href=$PHP_SELF?page=$i$queryString>".($i+1)."</a> ";
    }
    if($endpage<$pages)
        echo "<b><a href=$PHP_SELF?page=".($page+$shownum*2)."$queryString>?</a></b> ... ";
    if($page<$pages)
        echo "<a href=$PHP_SELF?page=$pages$queryString>尾页</a>";
}
//显示带分类的分页
function showpage1()
{
$fenlei=$_GET["fenleiid"];
    global $page,$pages,$prepage,$nextpage,$queryString; //param from genpage function
    $shownum =10/2;
    $startpage = ($page>=$shownum)?$page-$shownum:0;
    $endpage = ($page+$shownum<=$pages)?$page+$shownum:$pages;
  
    echo "共".($pages+1)."页: ";
    if($page>0)echo "<a href=$PHP_SELF?fenleiid=$fenlei&page=0$queryString>首页</a>";
    if($startpage>0)
        echo " ... <b><a href=$PHP_SELF?fenleiid=$fenlei&page=".($page-$shownum*2)."$queryString>?</a></b>";
    for($i=$startpage;$i<=$endpage;$i++)
    {
        if($i==$page)    echo " <b>[".($i+1)."]</b> ";
        else        echo " <a href=$PHP_SELF?fenleiid=$fenlei&page=$i$queryString>".($i+1)."</a> ";
    }
    if($endpage<$pages)
        echo "<b><a href=$PHP_SELF?fenleiid=$fenlei&page=".($page+$shownum*2)."$queryString>?</a></b> ... ";
    if($page<$pages)
        echo "<a href=$PHP_SELF?fenleiid=$fenlei&page=$pages$queryString>尾页</a>";
}
?>
2）两个调用
第一个
<?php
$sql="select * from liuyan order by ly_id desc";
genpage($sql); //只需要正常代码加上这一行就ok。
$conn=mysql_query($sql,$connec);
while($rs=mysql_fetch_array($conn)){
?>
第二个
<?php
}
?>
<?php
showpage(); //显示页
?>
<?php
mysql_close();
    
?>