SqlDependency失败，因为无法通知或提供了SELECT语句

Question

我正在尝试使用SqlDependency，并且阅读了Microsoft的文章和Creating a Query for Notification。我多次检查，似乎都满足了文章中提到的要求。这是我的代码。

private void InitialSqlDependency()
    {
        using (var connection = new SqlConnection(_connString))
        {
            connection.Open();
            string message = string.Empty;

            string query = @"SELECT ModifiedOn FROM [dbo].[ContainerTransactions]";

            using (var command = new SqlCommand(query, connection))
            {
                command.Notification = null;

                SqlDependency dependency = new SqlDependency(command);
                dependency.OnChange += new OnChangeEventHandler(Dependency_OnChange);

                if (connection.State == ConnectionState.Closed)
                    connection.Open();

                SqlDataReader dr = command.ExecuteReader();
                if (dr.HasRows)
                {
                    dr.Read();
                    message = dr[0].ToString();
                }
            }
        }
    }

    private void Dependency_OnChange(object sender, SqlNotificationEventArgs e)
    {
        _logger.Debug("ContainerWatch Dependency Fired!");

        if (e.Type == SqlNotificationType.Change)
        {
            _logger.Debug("ContainerWatch Change Fired!");

            this.InitialSqlDependency();
        }
    }

但是，它始终无法订阅。而且我看到Query Notification Permissions返回了Query，这意味着A SELECT statement that cannot be notified or was provided. SqlNotificationInfo

SELECT语句非常简单，是否有导致失败的可能原因？

Answer 1

我找到了根本原因，因为The statement must not reference tables with computed columns。我在下面使用查询查看计算所得的列

SELECT * FROM sys.computed_columns WHERE object_id = OBJECT_ID('ContainerTransactions')

因此，我想我不能在此表上使用SqlDependency。