[backend] gin-gorm-sqlite

[alphawyu]

gin for web service
gorm for datastore (RDbms) independent persistence
sqlite (in memory) good for the show case

[alphawy45]

never mind.
this https://github.com/gothinkster/golang-gin-realworld-example-app very good gin/gorm sqlite impl already exists in the show case.