Transactions
The .NET Framework provides an integration between XML Web services and Microsoft DTC distributed transactions. You can cause a method that is exposed using the WebMethod attribute to start a DTC transaction using the Transaction property of the WebMethod attribute.
[WebMethod(TransactionOption=TransactionOption.Required)]
public DataSet GetBookByTitle(string title)
{
DataSet ds;
SqlCommand cmd;
SqlDataAdapter dsCmd;
SqlParameter param;
SqlConnection conn;
ds=new DataSet();
conn=new SqlConnection(
"user id=sa;password=;initial
catalog=DevDotNet;data source=localhost");
cmd=new SqlCommand("GetBooksByTitle",conn);
cmd.CommandType=CommandType.StoredProcedure;
param=cmd.Parameters.Add(new
SqlParameter("@Title",SqlDbType.NVarChar,255));
param.Value=title;
param.Direction=ParameterDirection.Input;
try
{
// Open the connection and execute the Command
conn.Open();
dsCmd=new SqlDataAdapter();
dsCmd.SelectCommand =cmd;
dsCmd.Fill(ds,"Titles");
return ds;
}
catch (Exception err)
{
// An error occurred, pass the exception up
throw err;
}
finally
{
// Close the Connection
if (conn.State == ConnectionState.Open)
conn.Close();
}
}
Using transactions in this manner will only coordinate a transaction involving multiple resource managers (say a database and an MSMQ message queue) from a single Web service. Microsoft, IBM, and BEA Systems are currently working on a specification called Web Services Transaction (WS-Transaction) that will allow you to coordinate a transaction between multiple XML Web services. See the following URL for more information: msdn.microsoft.com/library/default.asp?url=/library/en-us/dnglobspec/html/ws-transaction.asp.