Sqlite Database problem in copying

Hi, I’m having some issues in copying SQLite database ( or maybe read it ), i’ve already tried a lots of codes but without any result, all what i want is to do a login page that verify user/password, please i need your help,
sometime i got an error that says " TypeError: Cannot read property ‘transaction’ of null "
i’d installed :

  • sqlite
  • cordova-plugin-dbcopy
  • and ng-cordova.min.js