我想從數(shù)據(jù)庫(kù)中選擇數(shù)據(jù)并將其分配到會(huì)話(huà)中。后來(lái)我想調(diào)用它并使用它..$sql = "SELECT * FROM users WHERE email = '$email' AND password =   '$password'";  $query = mysqli_query($mysqli, $sql) or die ("Error: " .   mysqli_error($mysqli));  $row = mysqli_num_rows($query);  if($row == 0)  {     echo "Invalid Username/Password. Click here to <a href =      'login.html'>Login</a>";  }  else  {     $sql = "SELECT accname FROM account WHERE email = '$email'";     $result=mysqli_query($mysqli,$sql);     $row=mysqli_fetch_all($result,MYSQLI_BOTH);     $_SESSION['accname']= array_column($rows, 'accname');     $r = mysqli_fetch_assoc($query);     $_SESSION['fname'] = $r['fname'];     $_SESSION['lname'] = $r['lname'];     $_SESSION['email'] = $r['email'];     header("Location: dashboard.php");   }