I've got a database by phpMyAdmin within the OpenShift-server. It's called "MyDatabase". It contains two tables: comment and user.
By the way. I also got a database by phpMyAdmin on my XAMPP localhost and it's exactly the same. My homepage on the OpenShift server has two function which the user can be registered and logged in and a commentary-function, but the user won't be registered in the user table, although the node.js code and the SQL code is correct. Only the comments will be saved in the table "comments" - the user names don't. Strangly my homepage and the database on the localhost works. Both, comments and users, will be saved in the database "MyDatabase".
I don't know, why the database on the OpenShift-Server doesn't work. Do you know why?
It's been solved today. The code wasn't the problem, because the source of my problem was the second database on my server. The second database also contains a table which called 'user'. I deleted this database and now my database works.
Sorry for opening this thread too early. Thank you for offering your help.