I have an alternative for it and it's 100% free/offline and it's called looping: Looping Officel website I am using it for more than 4 years now (it only has a French version so good luck bro) and it's dedicated only for database diagrams and SQL generation (you can configure it to your DBMS if you don't find it in the prebuilt ones, and on top of that you can add code like rules and functions ...)