PHP Smarty 模板 if函數 foreach函數

從數據庫查詢數據，瀏覽器以表格形式顯示

模板頁面

<table border="1" width="800" align="center">
<caption>用戶信息表</caption>
            <{foreach $tdname as $val}>
                            <th><{$val}></th>
            <{/foreach}>
            <{foreach $users as $user}>        
                    <{if $user@first}>
                            <tr bgcolor="red">
                    <{elseif $user@last}>
                            <tr bgcolor="yellow">
                    <{elseif $user@index is even}>
                            <tr bgcolor="pink">
                    <{else}>
                            <tr bgcolor="gray">
                    <{/if}>                    
                            <{foreach     $user as $val}>
                                    <td align="center">
                                    <{$val}>
                                    </td>
                            <{/foreach}>
                    </tr>
                    <{foreachelse}>
                    沒有用戶查詢出來！
            <{/foreach}>
</table>

PHP頁面

<?php 
//創建smarty對象
require_once './libs/Smarty.class.php';
//定義根目錄
define('ROOT', str_replace("\\", "/",dirname(__FILE__))."/");
//實例化Smarty類
$smarty=new Smarty();
//設定定界符
$smarty->left_delimiter="<{";
$smarty->right_delimiter="}>";
//設置為false 定界符號左右可以有空格
$smarty->auto_literal = false;

//添加一個插件的目錄
//$smarty->setPluginsDir(ROOT."/libs/myplugins/");

//注意添加一個插件,要把系統默認設置的路徑加入 否則不能使用默認系統的插件
$smarty->setPluginsDir(array(
    ROOT."/libs/plugins/",//系統默認設置的路徑
    ROOT."/libs/myplugins/",//自定義的
));

//連接數據庫
const  DSN = 'mysql:host=localhost;dbname=test';
const   DBUSER = 'root';
const   DBPWD     = 'root';
try{
    $pdo = new PDO(DSN, DBUSER,DBPWD);
}catch(PDOException $e){
    echo "數據庫連接失敗:".$e->getMessage();
    exit;
}
$query = "select id, username, password,email from users";
$stmt = $pdo->prepare($query);
$stmt ->execute();
$users = $stmt->fetchAll(PDO::FETCH_ASSOC);
//var_dump($users);

$smarty->assign('users',$users);

$query = "desc users";
$stmt = $pdo->prepare($query);
$smarty->assign("users",$users);
$stmt ->execute();
$tdname = $stmt->fetchAll(PDO::FETCH_COLUMN);
//var_dump($tdname);

$smarty->assign('tdname',$tdname);

//變量輸出
$smarty->display('hello.tpl');

?>

瀏覽器顯示