Module development and code questions

We are in the process of upgrading to Drupal 10 but wants to know if it has a module/plug in for handling Floor plans.

Benneth

Hi,

Please let me know if it's possible to make article locked by permission, and make it avaliable to read only by scan QR Code (via phone).

Thanks for any suggestions.

Please, note that I'm completly new to Druapal (after few years with Joomla, I decided to learn something new).

Thank you!

Hi my site is running fine on multi server databases(2). Now there is a requirement in which 1 need to run a join query(3 joins) in that I need to get 1st and 3rd joins record from server1 db and 2nd join record from server2. I am not understanding how I can run such a query. Need you help.

I am using drupal 8.4

In looking at the Documentation in a REST POST of a Comment I saw 

https://www.drupal.org/docs/drupal-apis/creating-entities-with-the-core-...

Hello

I'm new to Drupal and trying to learn how it works. I've created an easy Hello World module, but when I test it I get the message "RuntimeException: Failed to start the session because headers have already been sent".

I've tried to search for it, read several possible questions, but couldn't solve it, most of the times because my little knowledge of Drupal.

I've found this solution, but really I don't know where to do it.