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MartenDb projections
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| public abstract class AppUser | |
| { | |
| public Guid Id { get; set; } | |
| } | |
| public class RegisteredUser : AppUser | |
| { | |
| public void Apply(Registered registered) | |
| { | |
| Username = registered.Username; | |
| } | |
| // remove this projection when user is disabled | |
| internal bool ShouldDelete(Disabled _) => true; | |
| public string Username { get; set; } | |
| } | |
| public class DisabledUser : AppUser | |
| { | |
| // start this projection when user is disabled | |
| public void Apply(Disabled disabled) | |
| { | |
| UserName = disabled.Username | |
| } | |
| public string Username { get; set; } | |
| } | |
| services.AddMarten(options => | |
| { | |
| options.Schema.For<AppUser>() | |
| .AddSubClass<RegisteredUser>() | |
| .AddSubClass<DisabledUser>(); | |
| }); | |
| // register user, then disable it as both events are on the same stream | |
| var registered = new Registered(username); | |
| var disabled = new Disabled(username); | |
| // store events | |
| session.Events.StartStream<AppUser>(streamId, registered, disabled); | |
| await session.SaveChangesAsync(); | |
| var user = session.Load<AppUser>(streamId); // (AppUser is DisabledUser)-> true | |
| var users = session.Query<AppUser>().ToList(); // Count -> 1 | |
| var registeredUser = session.Load<RegisteredUser>(streamId); // -> null | |
| var disabledUser = session.Load<DisabledUser>(streamId); // -> not null |
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