.NET/Java PDF, Tiff, Barcode SDK Library

/// The worker is paramaterized by its internal state type /// /// Percentage progress is based on the iteration number Cancellation checks /// are made at each iteration Implemented via an internal BackgroundWorker type IterativeBackgroundWorker<'a>(oneStep:('a -> 'a), initialState:'a, numIterations:int) = let worker = new BackgroundWorker(WorkerReportsProgress=true, WorkerSupportsCancellation=true).

vb.net qr code generator source code, telerik winforms barcode, winforms code 128, vb.net generate gs1 128, vb.net generator ean 13 barcode, vb.net pdf417, c# remove text from pdf, find and replace text in pdf using itextsharp c#, vb.net data matrix generator vb.net, c# remove text from pdf,

This chapter examines some of the security issues involved in a three-tier architecture that uses connection pooling. In particular, it delves into various alternatives of mapping an application end user to a database end user, and different ways in which an application can authenticate to the database on behalf of an end user. You ll also learn about the proxy authentication feature.

txtFirstName.Text = cm.Parameters["@fname"].Value.ToString(); txtLastName.Text = cm.Parameters["@lname"].Value.ToString(); tsAuthor.TimestampValue = cm.Parameters["@ts"].Value; pnEdit.Visible = true; } Notice how you re retrieving values using output parameters built right into our command text. This statement is executed with ExecuteNonQuery, which means the overhead of creating a result set is never incurred. This data access method is screaming fast, especially for dynamically generated SQL. You get the timestamp value back as an output parameter as well, and pass it right along to your user control, leaving it typed as an Object (basically untyped). This is fine, because the user control knows it s a byte array and converts to a string for streaming to the client. The user can now edit to his heart s content, and when done, click the Save button. Here you re using dynamic SQL with parameters built in again, but this time they re all input parameters (again, from Concurrency3.aspx). protected void btnSave_Click(object sender, EventArgs e) { SqlConnection cn = new SqlConnection( ConfigurationManager.ConnectionStrings ["localPubs"].ConnectionString); SqlCommand cm = new SqlCommand( "update authors_ts set au_fname = @fname, " + "au_lname = @lname where au_id = @id " + "and ts = @ts", cn); cm.Parameters.Add("@id", SqlDbType.Char, 11) .Value = ddlAuthors.SelectedValue; pm = cm.Parameters.Add("@ts", SqlDbType.Timestamp); pm.Value = tsAuthor.TimestampValue; cm.Parameters.Add("@fname", SqlDbType.VarChar, 20) .Value = txtFirstName.Text; cm.Parameters.Add("@lname", SqlDbType.VarChar, 40) .Value = txtLastName.Text; cn.Open(); int i = cm.ExecuteNonQuery(); cn.Close(); if (i == 1) lblOutput.Text = "Data saved"; else lblOutput.Text = "Concurrency error"; pnEdit.Visible = false; BindList(); }

// Create the events that we will later trigger let triggerCompleted,completed = IEvent.create() let triggerError ,error = IEvent.create() let triggerCancelled,cancelled = IEvent.create() let triggerProgress ,progress = IEvent.create() do worker.DoWork.Add(fun args -> // This recursive function represents the computation loop. // It runs at "maximum speed", i.e. is an active rather than // a reactive process, and can only be controlled by a // cancellation signal. let rec iterate state i = // At the end of the computation terminate the recursive loop if worker.CancellationPending then args.Cancel <- true elif i < numIterations then // Compute the next result let state' = oneStep state // Report the percentage computation and the internal state let percent = int ((float (i+1)/float numIterations) * 100.0) do worker.ReportProgress(percent, box state); // Compute the next result iterate state' (i+1) else args.Result <- box state iterate initialState 0) do worker.RunWorkerCompleted.Add(fun args -> if args.Cancelled then triggerCancelled() elif args.Error <> null then triggerError args.Error else triggerCompleted (args.Result : > 'a)) do worker.ProgressChanged.Add(fun args -> triggerProgress (args.ProgressPercentage,(args.UserState : > 'a))) member member member member x.WorkerCompleted x.WorkerCancelled x.WorkerError x.ProgressChanged = = = = completed cancelled error progress

In this chapter, you ll look at some of the issues related to locking in Oracle. In particular, you ll learn about the infamous lost update problem and various ways to address it. Along the way, you ll examine different strategies to implement two solutions to the lost update problem, namely optimistic locking and pessimistic locking. You ll also compare these two solutions and determine when to use each strategy.