SqlDependency.Start Method (String, String)
Starts the listener for receiving dependency change notifications from the instance of SQL Server specified by the connection string using the specified SQL Server Service Broker queue.
Assembly: System.Data (in System.Data.dll)
[HostProtectionAttribute(SecurityAction.LinkDemand, ExternalThreading = true)] public static bool Start( string connectionString, string queue )
- Type: System.String
The connection string for the instance of SQL Server from which to obtain change notifications.
- Type: System.String
An existing SQL Server Service Broker queue to be used. If null, the default queue is used.
Return ValueType: System.Boolean
true if the listener initialized successfully; false if a compatible listener already exists.
The connectionString parameter is NULL.
The connectionString parameter is the same as a previous call to this method, but the parameters are different.
The method was called from within SQLCLR.
The caller does not have the required SqlClientPermission code access security (CAS) permission.
A subsequent call to the method has been made with an equivalent connectionString parameter but a different user, or a user that does not default to the same schema.
Also, any underlying SqlClient exceptions.
The HostProtectionAttribute attribute applied to this type or member has the following Resources property value: ExternalThreading. The HostProtectionAttribute does not affect desktop applications (which are typically started by double-clicking an icon, typing a command, or entering a URL in a browser). For more information, see the HostProtectionAttribute class or SQL Server Programming and Host Protection Attributes.
This method starts the listener for the AppDomain for receiving dependency notifications from the instance of SQL Server specified by the connectionString parameter. This method may be called more than once with different connection strings for multiple servers.
If no queue name is specified, SqlDependency creates a temporary queue and service in the server that is used for the entire process, even if the process involves more than one AppDomain. The queue and service are automatically removed upon application shutdown.
Multiple calls to the Start method can be made, subject to the following restrictions:
Multiple calls with identical parameters (the same connection string, queue, and Windows credentials in the calling thread) are valid.
Multiple calls with different connection strings are valid as long as:
Each connection string specifies a different database, or
Each connection string specifies a different user, or
The calls come from different application domains.
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.