qr code generator c# code project ChAPTER 11 in C#.NET

Encoder QR Code 2d barcode in C#.NET ChAPTER 11

652 ChAPTER 11
Quick Response Code Drawer In Visual C#.NET
Using Barcode generator for Visual Studio .NET Control to generate, create QR Code image in .NET framework applications.
www.OnBarcode.com
Recognizing QR-Code In Visual C#.NET
Using Barcode decoder for .NET framework Control to read, scan read, scan image in .NET applications.
www.OnBarcode.com
Connecting to and Querying Data with LINQ
Paint Barcode In C#.NET
Using Barcode drawer for VS .NET Control to generate, create bar code image in .NET framework applications.
www.OnBarcode.com
Recognize Bar Code In Visual C#
Using Barcode recognizer for .NET Control to read, scan read, scan image in VS .NET applications.
www.OnBarcode.com
coId = Guid.NewGuid(); company.Rows.Add(coId, "Contoso"); empId = Guid.NewGuid(); employee.Rows.Add(empId, coId, "SueLast", "SueFirst", 20.00); empId = Guid.NewGuid(); employee.Rows.Add(empId, coId, "TomLast", "TomFirst", 68.00); empId = Guid.NewGuid(); employee.Rows.Add(empId, coId, "MikeLast", "MikeFirst", 18.99);
Generate QR-Code In Visual Studio .NET
Using Barcode drawer for ASP.NET Control to generate, create QR Code image in ASP.NET applications.
www.OnBarcode.com
Printing QR-Code In .NET Framework
Using Barcode generator for .NET Control to generate, create QR Code JIS X 0510 image in Visual Studio .NET applications.
www.OnBarcode.com
USING THE DATAADAPTER
Draw QR Code 2d Barcode In VB.NET
Using Barcode drawer for VS .NET Control to generate, create QR Code 2d barcode image in VS .NET applications.
www.OnBarcode.com
Generate Barcode In C#.NET
Using Barcode creation for VS .NET Control to generate, create barcode image in .NET framework applications.
www.OnBarcode.com
The DbDataAdapter object is used to retrieve and update data between a DataTable and a data store (such as a SQL Server database). The DbDataAdapter is derived from the DataAdapter class and is the base class of the provider-specific DbDataAdapter classes. Provider-specific versions of DbDataAdapter are created for each type of provider, such as SQL Server, Oracle, and XML. The DbDataAdapter class has the SelectCommand property that you use to define how data is to be retrieved. The SelectCommand must contain a valid DbCommand object, which must have a valid connection. You can also use DbDataAdapter to update changes to the data source. You ll learn more about this in the next section.) The DataAdapter.Fill method moves data from the data store to the DataTable object that you pass into this method. The Fill method has several overloads, some of which accept only a DataSet as a parameter. When a DataSet is passed to the Fill method, a new DataTable object is created in the DataSet if a source DataTable object is not specified. The following code uses the System.Configuration.ConfigurationManager to read the connection string from a Web.config file. It then uses System.Data.Common.DbConnection to represent a database connection. It also uses System.Data.SqlClient to work directly with a SQL Server database. Finally, it shows how you can use the DataAdapter.Fill method to load a DataTable directly from a SQL Server database.
Creating PDF 417 In Visual C#
Using Barcode maker for .NET Control to generate, create PDF-417 2d barcode image in VS .NET applications.
www.OnBarcode.com
Encoding UPC Symbol In C#.NET
Using Barcode generation for Visual Studio .NET Control to generate, create UPC-A Supplement 5 image in Visual Studio .NET applications.
www.OnBarcode.com
Sample of Visual Basic Code Dim pubs As ConnectionStringSettings pubs = ConfigurationManager.ConnectionStrings("PubsData") Dim connection As DbConnection = New SqlConnection() connection.ConnectionString = pubs.ConnectionString Dim cmd As SqlCommand = CType(connection.CreateCommand(), SqlCommand) cmd.CommandType = CommandType.Text cmd.CommandText = "SELECT pub_id, pub_name FROM publishers" Dim pubsDataSet As New DataSet("Pubs") Dim da As New SqlDataAdapter(cmd) da.Fill(pubsDataSet, "publishers") Sample of C# Code ConnectionStringSettings pubs = ConfigurationManager.ConnectionStrings["PubsData"]; DbConnection connection = new SqlConnection(pubs.ConnectionString);
Linear Encoder In Visual C#.NET
Using Barcode creation for .NET Control to generate, create 1D Barcode image in VS .NET applications.
www.OnBarcode.com
Draw UPCE In Visual C#
Using Barcode maker for .NET Control to generate, create UPC-E Supplement 2 image in .NET applications.
www.OnBarcode.com
Lesson 2: LINQ and ADO.NET
Printing UPC A In Objective-C
Using Barcode generation for iPhone Control to generate, create UCC - 12 image in iPhone applications.
www.OnBarcode.com
Code-128 Drawer In None
Using Barcode generator for Online Control to generate, create Code-128 image in Online applications.
www.OnBarcode.com
ChAPTER 11
Draw EAN 128 In .NET Framework
Using Barcode creation for .NET Control to generate, create EAN / UCC - 14 image in VS .NET applications.
www.OnBarcode.com
Recognize PDF-417 2d Barcode In Visual Studio .NET
Using Barcode scanner for VS .NET Control to read, scan read, scan image in VS .NET applications.
www.OnBarcode.com
SqlCommand cmd = (SqlCommand)connection.CreateCommand(); cmd.CommandType = CommandType.Text; cmd.CommandText = "SELECT pub_id, pub_name FROM Publishers"; SqlDataAdapter da = new SqlDataAdapter(cmd); DataSet pubsDataSet = new DataSet("Pubs"); da.Fill(pubsDataSet, "publishers");
Generating Code 39 Full ASCII In Visual Studio .NET
Using Barcode drawer for VS .NET Control to generate, create Code 39 Extended image in VS .NET applications.
www.OnBarcode.com
Code 39 Encoder In None
Using Barcode creation for Software Control to generate, create Code 3 of 9 image in Software applications.
www.OnBarcode.com
Saving Changes to the Database
Printing PDF 417 In None
Using Barcode printer for Font Control to generate, create PDF 417 image in Font applications.
www.OnBarcode.com
Painting PDF417 In None
Using Barcode creator for Software Control to generate, create PDF417 image in Software applications.
www.OnBarcode.com
The DataAdapter.Update method retrieves the changes from a DataTable object and executes the appropriate InsertCommand, UpdateCommand, or DeleteCommand to send each change to the data store on a row-by-row basis. The Update method retrieves the DataRow objects that have been changed by looking at the RowState property of each row. If the RowState is anything but Unchanged, the Update method sends the change to the database. For the Update method to work, all four commands (select, insert, update, and delete) must be assigned to the DbDataAdapter. Normally this means creating individual DbCommand objects for each command. You can easily create the commands by using the DbDataAdapter configuration wizard, which starts when a DbDataAdapter is dropped onto a webpage. The wizard can generate stored procedures for all four commands. Another way to populate the DbDataAdapter object s commands is to use the DbCommandBuilder object. This object creates the InsertCommand, UpdateCommand, and DeleteCommand as long as a valid SelectCommand exists.
SAVING CHANGES TO THE DATABASE IN BATCHES
One way to increase update performance is to send the changes to the database server in batches instead of sending changes on a row-by-row basis. You can do this by assigning a value to the DbDataAdapter object s UpdateBatchSize property. This property defaults to 1, which causes each change to be sent to the server on a row-by-row basis. Setting the value to 0 instructs the DbDataAdapter object to create the largest possible batch size for changes, or you can set the value to the number of changes you want to send to the server in each batch. Setting the UpdateBatchSize to a number greater than the number of changes that need to be sent is equivalent to setting it to 0. You can confirm that the changes are being sent to the database server in batches by adding a RowUpdated event to the DbDataAdapter object. The event handler method exposes the number of rows affected in the last batch. When the UpdateBatchSize is set to 1, the RecordsAffected property is always 1. In the following code, the Publishers table contains eight rows. The pubsDataSet is filled, and then the pub_name field is modified on all eight rows. Before the Update method is executed, the UpdateBatchSize is changed to 3. When the Update method is executed, the changes are sent to the database as a batch of three changes, another batch of three changes, and, finally, a batch of two changes. This code contains a RowUpdated event handler to collect batch information, which is displayed after the Update method is executed.
Copyright © OnBarcode.com . All rights reserved.