SqlCacheDependency not working

Question

I would like to add SqlCacheDependency to my app. So I desided to create littel tesp project and confronted with difficulties. I use MSSQL 2008. I create new db with table Lines and added several rows. I executed:

ALTER DATABASE ForTest SET ENABLE_BROKER 

in managmeng studio.

Aspx page:

public partial class WebForm1 : System.Web.UI.Page
  {
    protected void Page_Load(object sender, EventArgs e)
    {
      if (!IsPostBack)
      {
       if (Cache["Lines"] == null)
       {
         string connectionString = 
           WebConfigurationManager.ConnectionStrings["ForTest"].ConnectionString;
         SqlConnection con = new SqlConnection(connectionString);
         string query = "SELECT dbo.Lines.Id, dbo.Lines.Value FROM dbo.Lines";
         SqlCommand cmd = new SqlCommand(query, con);
         SqlDataAdapter adapter = new SqlDataAdapter(cmd);

         DataSet ds = new DataSet();
         adapter.Fill(ds, "Lines"); 

         SqlCacheDependency empDependency = new SqlCacheDependency(cmd);
         Cache.Insert("Lines", ds, empDependency); 
       }
      }
    }

    protected void btnResult_OnClick(object sender, EventArgs e)
    {
      var result = Cache["Lines"];
    }
}

I run this page and add lines to Cache then I add row in managment studio and when I click on button I expect that the cache will be changed but cache remains old. I can't find what I do wrong :( Could you give me some hint how I can solve this problem?

Thanks

Update: I forger to say that in global.aspx I run:

SqlDependency.Start(
    WebConfigurationManager.ConnectionStrings["ForTest"].ConnectionString
);

Answer 1

I had a similar issue. This article: Troubleshooting SqlCacheDependency in SQL Server 2008 and SQL Server 2005 helped me a lot then.

In a few words: the databse was restored from a backup, and the original Windows user that created the database was no longer available. So I changed the database ownership to a valid login, something similar to:

ALTER AUTHORIZATION ON DATABASE::[my_perfect_database_name] TO [sa];

and it works like a charm now.

How did I find the source of the issue? I run the query SELECT * FROM sys.transmission_queue and found the next data in the transmission_status column:

An exception occurred while enqueueing a message in the target queue. Error: 15517, State: 1. Cannot execute as the database principal because the principal "dbo" does not exist, this type of principal cannot be impersonated, or you do not have permission.

This message gave me a key to solving the problem.