How do you implement Optimistic Concurrency and resolve conflicts with RowVersion in EF Core?

Short answer

Add a [Timestamp] byte[] RowVersion property; an update is rejected with DbUpdateConcurrencyException if another user changed the row since it was read.

Explanation

Optimistic Concurrency does not hold database locks while a user reads data. A RowVersion column (or xmin in PostgreSQL) automatically gets a new binary value whenever the row changes. On save, EF Core issues UPDATE ... WHERE Id = @id AND RowVersion = @originalRowVersion. If the value changed, no row is updated and EF Core throws a concurrency exception, letting you merge changes or notify the user.

Code example

public class BankAccount {
    public int Id { get; set; }
    public decimal Balance { get; set; }

    [Timestamp]
    public byte[] RowVersion { get; set; } = null!;
}

Common mistakes

• Ignoring DbUpdateConcurrencyException, losing user changes or overwriting them blindly (Blind Overwrite).

Follow-up questions

• How do you use Global Query Filters for soft deletion and Multi-Tenancy in EF Core?

Sources

• Microsoft Learn — Handling Concurrency Conflicts in EF Core