Have been a MySQL user all my career and now, with my new job, they use MS SQL Server databases. Never really encountered it before, but I know there are a lot of differences (sprung on me during the Technical Test I got!)
use database library’s like adodb or PDO and many more.
for database intrections use tools like ORM. this way database will never matter
you can use mysql or mssql or anything in backend and yet you have same syntax for all your projects.