php如何连接mysql并查询数据

<?php
/**
 * Created by PhpStorm.
 * User: karnetkarnet
 * Date: 17/3/3
 * Time: 09:46
 */
define('SQL_HOST','localhost');//数据库地址
define("SQL_USER","root");//数据库用户名
define("SQL_PASSWORD","");//数据库密码
define("SQL_DATABASE","shop");//连接的数据库名字
define("SQL_PORT","3306");//数据库端口号,默认为3306
//define("SQL_SOCKDET","");
$mysql = mysqli_connect(SQL_HOST,SQL_USER,SQL_PASSWORD,SQL_DATABASE,SQL_PORT) or die(mysqli_error());
//连接不上切换数据库
//mysqli_select_db(SQLDATABASE);
//查询语句
$sql = "select* from goods";
//查询
$results = $mysql -> query($sql);
print_r($results);
//遍历循环打印数据
while ($row = mysqli_fetch_array($results))
{
// print_r($row);
 echo $row['goods_name'];
 echo "<br>";
}
//释放
mysqli_free_result($results);
//关闭连接
mysqli_close($mysql);
?>