php 多功能搜索

$flag=$_POST['flag'];
$sosoval=$_POST['keyword'];
$sosoquery="where 1=1 ";
if(!empty($sosoval)&&$flag!=='-1'){
//$sosoquery.="and (title like '%$sosoval%') or (keyword like '%$sosoval%') or (author like '%$sosoval%')";
if($flag=='1'){
	$sosoquery.="and (author like '%$sosoval%')";
}elseif ($flag=='2'){
	$sosoquery.="and (title like '%$sosoval%')";
}else{
	$sosoquery.="and (keyword like '%$sosoval%')";
}
} $sql="select * from article $sosoquery order by id desc";
$rs=$db->query($sql);
$date=array();
while ($row=$db->fetch_array($rs)){
	$date[]=$row;
}
$tpl->assign('soso',$date);
$tpl->assign('appname','信息示例');
$tpl->display('index/up.tpl');