php操作mysql数据库的基本类

<?php
$dbhost = 'localhost';
$dbuser = 'root';
$dbpass = '123456';
$dbname = 'products';
$connect = mysql_connect($dbhost, $dbuser, $dbpass);
if (!$connect) exit('数据库连接失败！');
mysql_select_db($dbname, $connect);
mysql_query('set names utf8');
//查询
$sql = "SELECT * FROM `category`";
$result = mysql_query($sql);
while ($row = mysql_fetch_array($result)) {
    echo $row['id'];
}
//插入
$sql = "INSERT INTO `category` (`id`,`name`) VALUES (NULL,'" . $name . "')";
$result = mysql_query($sql);
if (mysql_affected_rows()) {
    echo '插入成功，插入ID为：', mysql_insert_id();
} else {
    echo '插入失败：', mysql_error();
}
//修改
$sql = "UPDATE `category` SET `name`='" . $name . "' WHERE `id`='" . $id . "'"; //开源代码phprm.com
$result = mysql_query($sql);
if (mysql_affected_rows()) {
    echo '修改成功！';
}
//删除
$sql = "DELETE FROM `category` WHERE `id`='" . $id . "'";
$result = mysql_query($sql);
if (mysql_affected_rows()) {
    echo '删除成功！';
}
//关闭连接
mysql_close($connect);