PHP测试MySQL数据库连接是否正常

$db_host = "数据库地址";
$db_user = "数据库用户名";
$db_pwd = "数据库密码";
$db_name = "数据库名";
$db_prefix = "数据库表前缀";
$link = @mysql_connect($db_host, $db_user, $db_pwd);
if(!$link){
exit("mysql connect failed");
}
else{
echo "mysql connect success";
}
if(!mysql_select_db($db_name, $link)){
exit("database ".$db_name." connct failed");
}
else{
echo "database ".$db_name." connect success";
}
$sql = "Select * from 某个表";
$result = mysql_query($sql);
echo $result;
while($row = mysql_fetch_row($result))
print_r($row);