C # – control over the number of users logged into my system

I have a procedure that controls the registration of all users who log on. I am trying to graphically enter the number of users logged into my system in a text box.

This is my procedure being performed

string sql1 = @"exec (gen).(sp_EBR_usuariosRegistrados) {0}";
 sql1 = string.Format(sql1, this.SysID);
 DataTable dtResultados = this.Ets.Api.Util.Db.GetDataTable(sql1).Return;

this.listViewDialogUserRegistered.DataSource = dtResultados;

The truth is that I don't know how to do it because my procedure controls all logged in users, but to show them the number that is logged in on the screen, I am somewhat lost in this area.

Print – Ghost printer in the print dialog box, but not in the printer control panel

I have a strange problem with ghost printers that seems to be different from what others have asked for. In my case, the ghost printer is only shown in the print dialog box. The printer is only called "print" and does not accept jobs. However, when I go to the printer control panel, everything looks normal.

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I am using Ubuntu 19.10.

Access Control List – Oracle Apex DBA_NETWORK_ACL_PRIVILEGES

I have a problem when I create a web source module as below

The endpoint URL could not be called.

An error occurred when calling the URL.

ORA-24247: access control list (ACL) network access denied
Either I've already done ACL steps


1 www.samples.openweathermap.org /sys/acls/http_permissions.xml 09A49A873E6F4D3296A277266F626D8F


1 /sys/acls/http_permissions.xml 09A49A873E6F4D3296A277266F626D8F APIS connect true false
2 /sys/acls/http_permissions.xml 09A49A873E6F4D3296A277266F626D8F APIS resolution true false

Please indicate whether a buddy knows how to access i jason data from an external website

Threat modeling for visitor access control

I'm trying to understand threat modeling, but it seems too elastic from restrictive requirements to general requirements.

Now I'm trying to understand it with some realistic examples. The first example that comes to mind is the physical access control of an office building where visitors have pre-approved restricted access and employees have unrestricted access. Every employee and authorized visitor receives an identity card to prevent this. Any official laptop should not go outside the office without permission. Every laptop has an RFID tag to prevent this.

Can someone help me understand the threat model in this example? Or can someone point out where similar analyzes have been carried out?

Remote control for Android with PC with local WiFi, without internet

I want to control an application in my Android phone via WiFi. Is there a way to control Android devices from the PC via local WiFi or an access point without internet !! I searched a lot, but all apps need internet. No free VNC server for Android either. Please, I have no problem rooting my Android, I also have an old Android. Any free app like vnc can work.

oc.optimization and control – advantages and disadvantages of using integer programming alone or combined integer and global optimization?

First, I'm not sure if this is the right question in this forum. But I searched for answers for a long time and also asked the "engineering" professors of my university, but I don't seem to get a mathematical answer.

I'm trying to solve a complex optimization problem that involves network and short path optimization, while solving nonlinear pressures, flows, and diameters. I can use one of the following methods:

  1. The first method is to use a mixed integer linear programming method
    (MILP) only and linearize the pressure, flow and diameter with
    piecewise linear approximation. The linearization has been done since
    MILP only uses linear equations and looks for an optimal solution.

  2. The second method is to use a combined local and global optimization
    Optimization method. Local optimization would use MILP first
    Find a solution to sub-problems where continuous optimization would be possible
    expensive to use (e.g. allocation of production). Then I would use one
    global optimization method using a derivative-free genetic algorithm
    disrupt the system (e.g. the network path) and
    find a better global solution. Whenever the system is disrupted
    The local MILP optimization is repeated.

I'm after recommendations, heads-ups, and things to look out for when implementing either of these methods. Is the second method mathematically acceptable compared to the first method?

MySQL Control Shutdown – Database Administrators Stack Exchange

We run a financial application with MySQL as a database.

For performance reasons, we use memory tables for some of our live tables, in which the data is populated every few milliseconds.

To ensure data consistency in all scenarios (planned and unplanned outages), we must ensure that the data in the storage tables is always preserved so that we can implement shutdown hooks, with the data being written normally in the event of a shutdown, tables and at startup restored.

Unfortunately I can't find a way to do this.

Any suggestions would be appreciated.

We use MySQL ver 5.7

8 – Custom node access control doesn't work with view access filter?

In some of my content types, I have the "Content Protection" checkbox. If this option is activated, this node should only be visible to registered users. If not marked – visible to everyone:

function hook_node_access($node, $op, $account) {

  // If $node is a string, the node has not yet been created. We don't care
  // about that case.
  if (is_string($node)) {
    return new AccessResultNeutral();
  if ($node->hasField('field_content_protect')) {
    $protected = ($node->field_content_protect->value == 1) ? TRUE : FALSE;
    $userId = $account->id();
    if ($protected && $userId == 0) {
      return new AccessResultForbidden();
  return new AccessResultNeutral();

And that works well when I try to access the node directly. If it is protected, anonymous users cannot access it.

Now I have a view that lists some of these nodes. I want to apply the same logic and do not exclude protected nodes for anonymous users. So I added filters from my point of view:

Content access: Access

But it doesn't work as expected. There is content for authenticated users, but for anonymous users the entire block content is simply missing?!? Nodes for which the "Content protection" field is not activated are also not listed?!? Why this? This filter has no options / settings.

I have another option to duplicate the view display, check the field directly, and display the first or second block view depending on the user, but this solution with content access filter looks more elegant.

Version control – problem with Drupal 7 Composer dependencies

When trying to install a juicebox that requires libraries, the dependencies do not result in a working configuration. This is because Juicebox defines a version requirement in the .info file that is not translated correctly into the corresponding Composer restriction.

Juicebox defines it dependencies as follows:

core = 7.x
dependencies() = image
dependencies() = libraries (>1.0)

This means that any version of libraries higher than 1.0 would work (i.e. 1.1, 2.0).

The following versions are installed when installing libraries and Juicebox with Composer:

"name": "drupal/juicebox",
"version": "dev-2.x",

"name": "drupal/libraries",
"version": "dev-1.x",

However, this does not correspond to the actual requirements in Drupal:

Enter the image description here

If you try to manually install the correct version of the libraries:

"drupal/juicebox": "^2.1",
"drupal/libraries": "^2.0",

it doesn't work and that composer update Outputs:

Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - Conclusion: remove drupal/juicebox 2.1.0
    - Conclusion: don't install drupal/juicebox 2.1.0
    - Conclusion: don't install drupal/libraries 2.5.0
    - Conclusion: don't install drupal/libraries 2.4.0
    - Conclusion: don't install drupal/libraries 2.3.0
    - Conclusion: don't install drupal/libraries 2.2.0
    - Conclusion: don't install drupal/libraries 2.1.0
    - Conclusion: don't install drupal/libraries 2.0.0
    - Conclusion: don't install drupal/libraries 2.0.0-alpha2
    - Installation request for drupal/juicebox ^2.1 -> satisfiable by drupal/juicebox(2.x-dev, 2.1.0).
    - Conclusion: don't install drupal/libraries 2.0.0-alpha1
    - drupal/juicebox 2.x-dev requires drupal/libraries ^1.1 -> satisfiable by drupal/libraries(1.x-dev).
    - Can only install one of: drupal/libraries(1.x-dev, 2.x-dev).
    - Can only install one of: drupal/libraries(2.x-dev, 1.x-dev).
    - Installation request for drupal/libraries ^2.0 -> satisfiable by drupal/libraries(2.x-dev, 2.5.0, 2.4.0, 2.3.0, 2.2.0, 2.1.0, 2.0.0, 2.0.0-alpha2, 2.0.0-alpha1).

This clearly shows the problem, namely that > by doing juicebox.info is translated into a composer restriction of ^1.1 it's not the same:

  • ^ in the composer everything means until the next major version
  • > in drupal .info Files means everything above

I didn't know where to post this issue since Drupal forums reported it as spam and I couldn't find a repository where this was implemented.