SqlDependency not working with Entity Framework

Question

I have an issue when trying to start the SqlDependency.

The error informs me: Keyword not supported: 'metadata'.

The connectionstring is the following when retrieved from the immediate window right before it crashes.

?objectContext.Connection.ConnectionString
 "metadata=res://*/YeagerTech.csdl|res://*/YeagerTech.ssdl|res://*/YeagerTech.msl;provider=System.Data.SqlClient;provider connection string=\"data source=Bill-PC;initial catalog=YeagerTech;integrated security=True;multipleactiveresultsets=True;App=EntityFramework\""

Here is the code. It crashes on the Start method. Apparently, it doesn't think the EF connectionstring is valid. Any idea of how I can correctly use this?

YeagerTechEntities dbContext = new YeagerTechEntities();

            ObjectContext objectContext = ((IObjectContextAdapter)dbContext).ObjectContext;

            SqlDependency.Start(objectContext.Connection.ConnectionString);

Answer 1

Because EF connection string is not valid for SqlDependency. It works only with EntityConnection but SqlDependency uses SqlConnection. So you must either use direct connection string in your dbContext or extract database connection string from entity connection.

Either:

var connectionString = dbContext.Database.Connection.ConnectionString;

Or

var connectionString = ((EnityConnection)objectContext.Connection).StoreConnection.ConnectionString;

Anyway EF doesn't play very well with SqlDependency. SqlDependency expects that you write SQL queries yourselves and have them under your control.

Answer 2

Actually, the code snippet that I got it to work is the following:

YeagerTechEntities dbContext = new YeagerTechEntities();

ObjectContext objectContext = ((IObjectContextAdapter)dbContext).ObjectContext;

Application["dbContext"] = dbContext;

objectContext.Connection.ConnectionString =    
   ConfigurationManager.ConnectionStrings["YeagerTechEntities"].ConnectionString;

SqlDependency.Start(((System.Data.EntityClient.EntityConnection)objectContext.Connection)
   .StoreConnection.ConnectionString);

YeagerTechEntities is the EF connectionstring.