影响PHP+MYSQL执行速度的写法对比
作者：
影响PHP+MYSQL执行速度的写法对比
复制代码 代码如下:
<?php
include_once("../db.php");
if($_GET[x2]==0 and $_GET[x1]==0)
{
$t=" s1='' ";
}else
{
if($_GET[x2]!=0)
{
$t=" x2='$_GET[x2]' ";
}else
if($_GET[x1]!=0)
{
$t=" x1='$_GET[x1]' and x2=0 ";
}
}
$query = "select count(*) from ask_member where $t ";
$result2 = mysql_db_query($DataBase, $query);
$r3 = mysql_fetch_array($result2);
$amount=$r3[0];
$page_size=5;
if($amount%$page_size==0 and $amount>0)
{
$pagecount=($amount/$page_size);
}else
{
$pagecount=intval($amount/$page_size)+1;
}
if($_GET==0)
{$_GET=1;}
if($_GET>$pagecount)
{$_GET=$pagecount;}
$page=$_GET;
$a=($_GET-1)*$page_size;
$query = "select tid,truename,school,study,city,logo,year,month,x1,x2 from ask_member where $t order by logo desc, logintime desc limit $a,$page_size ";
$result = mysql_db_query($DataBase, $query);
while($r2[] = mysql_fetch_array($result))
{
}
foreach($r2 as $rr2)
{
$query = "select name,tid from ask_school where tid='$rr2[x2]' ";
$result2 = mysql_db_query($DataBase, $query);
$r5[] = mysql_fetch_array($result2);
}
$n=count($r2)-1;
?>
<?php
for($i=0;$i<$n;$i++)
{
?>
<table width="100%" border="0" cellpadding="5" cellspacing="1" bgcolor="#57ACF2">
<tr>
<td align="center" bgcolor="#FFFFFF">
<table width="690" border="0" cellspacing="0" cellpadding="0">
<tr valign="middle">
<td width="80"><img
src="../ask/center/memberlogo/<?php if($r2[$i][logo]!=''){echo $r2[$i][logo];}else if ($r2[$i][sex]=='女'){echo "default.gif";}else{echo "default3.gif";} ?>" border=0 width="100" height="127" onload="javascript:DrawImage(this,100,127)"></td>
<td width="430"><strong><?php echo $r2[$i][truename]; ?> - <font color="#85B000">信息 :)</font></strong><br>
字段一：<a href="#" class="blue"><?php echo $r5[$i][name]==''?'内容':$r5[$i][name]; ?></a> <br>
字段二：<a href="#" class="blue"><?php echo $r2[$i][study]; ?></a><br>
字段三：<a href="#" class="blue"><?php echo $r2[$i][year]; ?><?php echo $r2[$i][month]; ?></a><br>
浏览：<a href="#" class="blue">一</a> <font color="#0E6FBE">|</font>
<a href="#" class="blue">二</a> <font color="#0E6FBE">|</font>
<a href="#" class="blue">三</a> </td>
<td width="180" align="right"><table width="110" border="0" cellpadding="0" cellspacing="1" bgcolor="#CCCCCC">
<tr>
<td height="20" align="center" bgcolor="#eeeeee"><a href="hello.php?tid=<?php echo $r2[$i][tid]; ?>">打个招呼</a></td>
</tr>
</table>
<table width="110" border="0" cellspacing="0" cellpadding="0">
<tr>
<td height="3"></td>
</tr>
</table>
<table width="110" border="0" cellpadding="0" cellspacing="1" bgcolor="#CCCCCC">
<tr>
<td height="20" align="center" bgcolor="#eeeeee"><a href="sendmessagelook.php?tid=<?php echo $r2[$i][tid]; ?>">其它操作</a></td>
</tr>
</table>
<table width="110" border="0" cellspacing="0" cellpadding="0">
<tr>
<td height="3"></td>
</tr>
</table>
<table width="110" border="0" cellpadding="0" cellspacing="1" bgcolor="#CCCCCC">
<tr>
<td height="20" align="center" bgcolor="#eeeeee"><a href="addfriend.php?tid=<?php echo $r2[$i][tid]; ?>">操作二</a></td>
</tr>
</table>
<table width="110" border="0" cellspacing="0" cellpadding="0">
<tr>
<td height="3"></td>
</tr>
</table>
<table width="110" border="0" cellspacing="0" cellpadding="0">
<tr>
<td height="3"></td>
</tr>
</table>
</td>
</tr>
</table>
</td>
</tr>
</table>
<table width="100%" border="0" cellspacing="0" cellpadding="0">
<tr>
<td height="10"></td>
</tr>
</table>
<?php
}
?>
include_once("../db.php");
if($_GET[x2]==0 and $_GET[x1]==0)
{
$t=" s1='' ";
}else
{
if($_GET[x2]!=0)
{
$t=" x2='$_GET[x2]' ";
}else
if($_GET[x1]!=0)
{
$t=" x1='$_GET[x1]' and x2=0 ";
}
}
$query = "select count(*) from ask_member where $t ";
$result2 = mysql_db_query($DataBase, $query);
$r3 = mysql_fetch_array($result2);
$amount=$r3[0];
$page_size=5;
if($amount%$page_size==0 and $amount>0)
{
$pagecount=($amount/$page_size);
}else
{
$pagecount=intval($amount/$page_size)+1;
}
if($_GET==0)
{$_GET=1;}
if($_GET>$pagecount)
{$_GET=$pagecount;}
$page=$_GET;
$a=($_GET-1)*$page_size;
$query = "select tid,truename,school,study,city,logo,year,month,x1,x2 from ask_member where $t order by logo desc, logintime desc limit $a,$page_size ";
$result = mysql_db_query($DataBase, $query);
while($r2[] = mysql_fetch_array($result))
{
}
foreach($r2 as $rr2)
{
$query = "select name,tid from ask_school where tid='$rr2[x2]' ";
$result2 = mysql_db_query($DataBase, $query);
$r5[] = mysql_fetch_array($result2);
}
$n=count($r2)-1;
?>
<?php
for($i=0;$i<$n;$i++)
{
?>
<table width="100%" border="0" cellpadding="5" cellspacing="1" bgcolor="#57ACF2">
<tr>
<td align="center" bgcolor="#FFFFFF">
<table width="690" border="0" cellspacing="0" cellpadding="0">
<tr valign="middle">
<td width="80"><img
src="../ask/center/memberlogo/<?php if($r2[$i][logo]!=''){echo $r2[$i][logo];}else if ($r2[$i][sex]=='女'){echo "default.gif";}else{echo "default3.gif";} ?>" border=0 width="100" height="127" onload="javascript:DrawImage(this,100,127)"></td>
<td width="430"><strong><?php echo $r2[$i][truename]; ?> - <font color="#85B000">信息 :)</font></strong><br>
字段一：<a href="#" class="blue"><?php echo $r5[$i][name]==''?'内容':$r5[$i][name]; ?></a> <br>
字段二：<a href="#" class="blue"><?php echo $r2[$i][study]; ?></a><br>
字段三：<a href="#" class="blue"><?php echo $r2[$i][year]; ?><?php echo $r2[$i][month]; ?></a><br>
浏览：<a href="#" class="blue">一</a> <font color="#0E6FBE">|</font>
<a href="#" class="blue">二</a> <font color="#0E6FBE">|</font>
<a href="#" class="blue">三</a> </td>
<td width="180" align="right"><table width="110" border="0" cellpadding="0" cellspacing="1" bgcolor="#CCCCCC">
<tr>
<td height="20" align="center" bgcolor="#eeeeee"><a href="hello.php?tid=<?php echo $r2[$i][tid]; ?>">打个招呼</a></td>
</tr>
</table>
<table width="110" border="0" cellspacing="0" cellpadding="0">
<tr>
<td height="3"></td>
</tr>
</table>
<table width="110" border="0" cellpadding="0" cellspacing="1" bgcolor="#CCCCCC">
<tr>
<td height="20" align="center" bgcolor="#eeeeee"><a href="sendmessagelook.php?tid=<?php echo $r2[$i][tid]; ?>">其它操作</a></td>
</tr>
</table>
<table width="110" border="0" cellspacing="0" cellpadding="0">
<tr>
<td height="3"></td>
</tr>
</table>
<table width="110" border="0" cellpadding="0" cellspacing="1" bgcolor="#CCCCCC">
<tr>
<td height="20" align="center" bgcolor="#eeeeee"><a href="addfriend.php?tid=<?php echo $r2[$i][tid]; ?>">操作二</a></td>
</tr>
</table>
<table width="110" border="0" cellspacing="0" cellpadding="0">
<tr>
<td height="3"></td>
</tr>
</table>
<table width="110" border="0" cellspacing="0" cellpadding="0">
<tr>
<td height="3"></td>
</tr>
</table>
</td>
</tr>
</table>
</td>
</tr>
</table>
<table width="100%" border="0" cellspacing="0" cellpadding="0">
<tr>
<td height="10"></td>
</tr>
</table>
<?php
}
?>
问题一:为什么要用
复制代码 代码如下:
<?php
while($r2[] = mysql_fetch_array($result))
{
}
foreach($r2 as $rr2)
{
$query = "select name,tid from ask_school where tid='$rr2[x2]' ";
$result2 = mysql_db_query($DataBase, $query);
$r5[] = mysql_fetch_array($result2);
}
?>
while($r2[] = mysql_fetch_array($result))
{
}
foreach($r2 as $rr2)
{
$query = "select name,tid from ask_school where tid='$rr2[x2]' ";
$result2 = mysql_db_query($DataBase, $query);
$r5[] = mysql_fetch_array($result2);
}
?>
复制代码 代码如下:
<?php
while($r2[] = mysql_fetch_array($result))
{
}
foreach($r2 as $rr2)
{
$query = "select name,tid from ask_school where tid='$rr2[x2]' ";
$result2 = mysql_db_query($DataBase, $query);
$r5[] = mysql_fetch_array($result2);
}
?>
while($r2[] = mysql_fetch_array($result))
{
}
foreach($r2 as $rr2)
{
$query = "select name,tid from ask_school where tid='$rr2[x2]' ";
$result2 = mysql_db_query($DataBase, $query);
$r5[] = mysql_fetch_array($result2);
}
?>
而不用:
复制代码 代码如下:
<?php
$j=0;
while($r2[$j] = mysql_fetch_array($result))
{
$query = "select name,tid from ask_school where tid='$r2[$j][x2]' ";
$result2 = mysql_db_query($DataBase, $query);
$r5[$j] = mysql_fetch_array($result2);
$j++;
}
?>
$j=0;
while($r2[$j] = mysql_fetch_array($result))
{
$query = "select name,tid from ask_school where tid='$r2[$j][x2]' ";
$result2 = mysql_db_query($DataBase, $query);
$r5[$j] = mysql_fetch_array($result2);
$j++;
}
?>
复制代码 代码如下:
<?php
$j=0;
while($r2[$j] = mysql_fetch_array($result))
{
$query = "select name,tid from ask_school where tid='$r2[$j][x2]' ";
$result2 = mysql_db_query($DataBase, $query);
$r5[$j] = mysql_fetch_array($result2);
$j++;
}
?>
$j=0;
while($r2[$j] = mysql_fetch_array($result))
{
$query = "select name,tid from ask_school where tid='$r2[$j][x2]' ";
$result2 = mysql_db_query($DataBase, $query);
$r5[$j] = mysql_fetch_array($result2);
$j++;
}
?>
答:因为PHP网站在运行过程中,真正影响速度的原因只有一个,那就是对MYSQL的读取,至于程序多运行一两次复制和拷贝,很难对速度造成影响.所以在读取MYSQL的时候,我宁愿多一次内存中的运算,也不愿有什么操作影响到对MYSQL的读取.
问题二:为什么不用模版写程序?
答:因为PHP已经是最好的模版引擎了,为什么还要用其它的模版呢?
问题三:为什么把大量的PHP代码放在<HTML>的上方,而不是放面HTML的下方?
答:这个是有很大区别的,其一:代码放在<HTML>上方,如果对代码进行修改的话,用DREARWEAVER再看下面视图的时候,不会有慢的感觉.
其二:大部分代码全部放在<HTML>上方,而不是放在<HTML>下方,对PHP脚本的解析运行有好处,可以减轻PHP服务器解析脚本的负担,并且符合模版及缓存设计思想.
问题三:为什么要用
view plaincopy to clipboardprint?
<?php
$query = "select count(*) from ask_member where $t ";
$result2 = mysql_db_query($DataBase, $query);
$r3 = mysql_fetch_array($result2);
$amount=$r3[0];
?>
<?php
$query = "select count(*) from ask_member where $t ";
$result2 = mysql_db_query($DataBase, $query);
$r3 = mysql_fetch_array($result2);
$amount=$r3[0];
?>
而不是用:
view plaincopy to clipboardprint?
<?php
$query = "select * from ask_member ";
$result2 = mysql_db_query($DataBase, $query);
$amount=mysql_num_rows($result2);
?>
<?php
$query = "select * from ask_member ";
$result2 = mysql_db_query($DataBase, $query);
$amount=mysql_num_rows($result2);
?>
答:第一种是对一条记录的查询,第二种是对所有记录的查询,两者速度有天壤之别.
问题四:为什么上面要多一行
view plaincopy to clipboardprint?
<?php
$n=count($r2)-1;
?>
<?php
$n=count($r2)-1;
?>
而不是下面直接用:
view plaincopy to clipboardprint?
<?php
for($i=0;$i<count($r2)-1;$i++)
{
?>
<?php
for($i=0;$i<count($r2)-1;$i++)
{
?>
答:应该尽量减少在<HTML>以下进行PHP的运算,如果过多地在<HTML>下进行运算的话,那就成了混编了.
问题五:为什么说以上代码是核心代码?
答:任何一位程序员都知道,读数据的分页读出是最常用的,我想大部分的PHP程序员30%的时间都是发在这个上面吧.
以上是我总结出的最快的写PHP的经验,请广大网友指正,如果觉得可以的话,希望所有人都能用这种方式来写程序,那样的话我以后安排一批PHP程序员进行分工协调的时候也好办多了.