$db_host = "localhost";
$db_user = "root"
$db_passwd ="db패스워드";
$db_name ="사용할 DB명";
$DBConn = mysqli_connect($db_host, $db_user, $db_passwd, $db_name);
mysqli_query($DBConn, "Set names utf8;"); //인코딩
DB연결 성공인지 확인 하는 방법
if($DBConn){
echo "성공";
}else{
echo "실패 : " . mysqli_connect_error();
}