/// <summary>
/// Import registrations from JSON file
/// </summary>
/// <param name="registrationsFileName">Name of the file to import</param>
/// <returns>
/// Collection of all imported registrations
/// </returns>
public async Task <IEnumerable <Registration> > ImportRegistrations(string registrationsFileName)
{
using var transaction = await Database.BeginTransactionAsync();
var fileContent = await File.ReadAllTextAsync("registrations.json");
var registrations = JsonSerializer.Deserialize <Registration[]>(fileContent);
await Registrations.AddRangeAsync(registrations);
await SaveChangesAsync();
await transaction.CommitAsync();
return(registrations);
}
