UC知道请高手帮我看看下面PHP代码
来源：百度知道 编辑：UC知道 时间：2024/05/25 12:08:46
小弟初学PHP，不太懂，主要是几个关键地方，希望帮我具体解释一下：
<?php
#filename="connection_php_mysql.htm"
#type="mysql"
#http="true"
$hostname_conn="hocalhost";
$database_conn="bookdb";
$username_conn="root";
$pawwword_conn="";
$conn=mysql_Pconnect($hostname_conn,$username_conn,$pawwword_conn) or trigger_error(mysql_error(),E_USER_error);
?>
<?php require_once('conn.php'); ?>
<?php
$colname_bookinfo="-1";
if (isset($_POST['booktype'])) {
$colname_bookinfo=(get_magic_quotes_gpc())?$_POST['booktype']:addslashes($_post['booktype']);
}
mysql_select_db($database_conn,$conn);
$query_bookinfo=sprintf("select * from booktable where booktype=%s",$colname_bookinfo);
mysql_query("SET NAMES 'GB2312'");
$row_bookinfo=mysql_fetch_assoc($bookinfo);
$totaqlrows_bookinf
<?php
#filename="connection_php_mysql.htm"
#type="mysql"
#http="true"
$hostname_conn="hocalhost";
$database_conn="bookdb";
$username_conn="root";
$pawwword_conn="";
$conn=mysql_Pconnect($hostname_conn,$username_conn,$pawwword_conn) or trigger_error(mysql_error(),E_USER_error);
?>
<?php require_once('conn.php'); ?>
<?php
$colname_bookinfo="-1";
if (isset($_POST['booktype'])) {
$colname_bookinfo=(get_magic_quotes_gpc())?$_POST['booktype']:addslashes($_post['booktype']);
}
mysql_select_db($database_conn,$conn);
$query_bookinfo=sprintf("select * from booktable where booktype=%s",$colname_bookinfo);
mysql_query("SET NAMES 'GB2312'");
$row_bookinfo=mysql_fetch_assoc($bookinfo);
$totaqlrows_bookinf
<?php
#filename="connection_php_mysql.htm"
#type="mysql"
#http="true"
$hostname_conn="hocalhost";
$database_conn="bookdb";
$username_conn="root";
$pawwword_conn="";
$conn=mysql_Pconnect($hostname_conn,$username_conn,$pawwword_conn) or trigger_error(mysql_error(),E_USER_error);
//上三行注释，不多说了连接数据库也不多说了；
?>
<?php require_once('conn.php'); ?>
<?php
$colname_bookinfo="-1";//初始化列名
if (isset($_POST['booktype'])) {//客户端接受图书种类，并安全过滤
$colname_bookinfo=(get_magic_quotes_gpc())?$_POST['booktype']:addslashes($_post['booktype']);
}
mysql_select_db($database_conn,$conn);//选择数据库
$query_bookinfo=sprintf("select * from booktable where booktype=%s",$colname_bookinfo);//SQL语句生成（为什么不写成"select * from booktable where booktype='%s'"）
mysql_query("SET