Q: Maybe it will be enough just edit mysql.php?A: Not in the slightest.Q: Someone in another forum told me that if OsTicket has PDO or ORM than it is possible to connect it to sql sever.A: osTicket is not ORM yet, its in the process of being transitioned, so it is not possible with out a ton of editing. You would have to utilize search across all the files of the core files to find all the places and edit the core files.Q: Can I post here link of topic from another forum?A: You can... but I dont see what the point would be since obv the person has no idea what the osTicket codebase is like if they are suggesting using PDO/ORM at this point.