php mysql交互

 1.接受数据  if($_POST){     $uname = trim($_POST['uname']);
    $pasd = md5($_POST['pasd']);
 2.查询数据库
    $conn = new MysqLi('localhost','root','root','qiye');
    $sql = "select * from admin where uname = '$uname' and pasd = '$pasd' ";
    $res = $conn->query($sql);
    if($conn->error){
        die($conn->error);
    }
    $info = $res->fetch_assoc();
  3. 判断数据
    if($res->num_rows > 0){
        setcookie('admin',$info['id']);
        header('Location:index.PHP');
    }else{
        $msg= '账号或者密码错误';
    }
    $conn->close();
}

4.获取MysqL报错信息$coon->error;

二 、文件上传


if($_FILES){
1.获取文件后缀
$temp=explode(".",$_FILES["img"]["name"]);
$extension=end($temp);
2.判断文件类型和大小
if($_FILES["img"]["name"]=="image/png" || $_FILES["img"]["name"]=="image/gif" || $_FILES["img"]["name"]=="image/jpeg" || $_FILES["img"]["name"]=="image/jpg" && $_FILES["img"]["size"]<=204800){
3.拼接文件名     $uname = '../uploads'.time().mt_rand(100,999).'.'.$extension;
4.存储到目录 move_uploaded_file($_FILES["img"]["tmp_name"],$uname);
5. 存入数据库

$conn = new MysqLi('localhost','root','root','denglu');
$sql = "insert into product (img) values('$uname')";
$res = $conn->query($sql);
var_dump($uname);
$conn->close();

6.调取数据库中的图片

$connn = new MysqLi('localhost','root','root','denglu');
$sqll = " select * from product where id =x";
$ress = $connn->query($sqll);
$r = $ress->fetch_assoc();
$connn->close();
?>

}
}

}