for me:
1 get sqlite3 from npm and vs2019 with c++ dev pack and python2 installed for compiling thing.
2 xx.db file in electron “user data” path.
db.js under src-electron folder(main process). CRUD thing is done here.
3 ipcRender under src( render process) and mainWindow.webcontent under src-electron(main process) to call db.js i mentioned above and sometimes get its callback data.