Why is the _session.FlushAsync(); called when updating a user using UserManager?

[barthamark]

When I implement a code where a User entity is updated and I save it using _userManager.UpdateAsync() the whole transaction is committed and even if there's an exception after that, the user entity is saved to the database. I'd expect to commit the transaction at the end of the request as every other items like content items.

The related code is here:

OrchardCore/src/OrchardCore/OrchardCore.Users.Core/Services/UserStore.cs

Line 219 in 78373a5

public async Task<IdentityResult> UpdateAsync(IUser user, CancellationToken cancellationToken = default)

[Piedone]

FlushAsync isn't committing the transaction, that's SaveChangesAsync. This was a change for the upcoming v3 version. It's only in v2.x.x that the transaction is committed, and that was wrong:

OrchardCore/src/OrchardCore/OrchardCore.Users.Core/Services/UserStore.cs

Line 235 in ac04f00

await _session.SaveChangesAsync();

[barthamark]

I see, thanks. It doesn't answer my question, though. Regardless, the UserStory UpdateAsync still commits transaction and I don't understand why.

[Piedone]

Because you use the 2.x version that commits the transaction, and you're confused because you're looking at the v3 version that doesn't.

[MikeAlhayek]

As @Piedone mentioned, FlushAsync only sends the pending changes to the database server—it doesn't actually commit them. On the other hand, SaveChangesAsync both writes the changes and commits the transaction.

One important difference between version 2 and version 3 is how commits are handled. In v2, it was possible to read dirty data—that is, data written to the database but not yet committed. For example, if you called UserService.UpdateAsync, another request could potentially retrieve the updated user data before the transaction was committed.

In v3, this behavior has changed. By default, reading dirty data is no longer allowed, improving data consistency across concurrent requests. Let me know if this answers your question.