what should database i use in my project ?
https://db-engines.com/en/system/Firebase+Realtime+Database%3BMySQL%3BSQLite
take a look to this report
thank you ahmad 
i use sql it is comfortable for me
i’m using it also … but i’m facing some problems with …
Depends on what you are building. But i assume you are most likely building a cross platform app. In this case, Firebase definitely. Firebase has realtime data transitioning capability, which MySQL lacks.