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Asked: 2026-05-10T15:55:20+00:00

I’ve got an ASP.NET app using NHibernate to transactionally update a few tables upon

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I’ve got an ASP.NET app using NHibernate to transactionally update a few tables upon a user action. There is a date range involved whereby only one entry to a table ‘Booking’ can be made such that exclusive dates are specified.

My problem is how to prevent a race condition whereby two user actions occur almost simultaneously and cause mutliple entries into ‘Booking’ for >1 date. I can’t check just prior to calling .Commit() because I think that will still leave be with a race condition?

All I can see is to do a check AFTER the commit and roll the change back manually, but that leaves me with a very bad taste in my mouth! 🙂

booking_ref (INT) PRIMARY_KEY AUTOINCREMENT

booking_start (DATETIME)

booking_end (DATETIME)

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1 Answer

    • make the isolation level of your transaction SERIALIZABLE (session.BeginTransaction(IsolationLevel.Serializable) and check and insert in the same transaction. You should not in general set the isolationlevel to serializable, just in situations like this.

    or

    • lock the table before you check and eventually insert. You can do this by firing a SQL query through nhibernate:

      session.CreateSQLQuery(‘SELECT null as dummy FROM Booking WITH (tablockx, holdlock)’).AddScalar(‘dummy’, NHibernateUtil.Int32); This will lock only that table for selects / inserts for the duration of that transaction.

    Hope it helped

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