- •Table of Contents
- •Preface
- •What is ASP.NET?
- •Installing the Required Software
- •Installing the Web Server
- •Installing Internet Information Services (IIS)
- •Installing Cassini
- •Installing the .NET Framework and the SDK
- •Installing the .NET Framework
- •Installing the SDK
- •Configuring the Web Server
- •Configuring IIS
- •Configuring Cassini
- •Where do I Put my Files?
- •Using localhost
- •Virtual Directories
- •Using Cassini
- •Installing SQL Server 2005 Express Edition
- •Installing SQL Server Management Studio Express
- •Installing Visual Web Developer 2005
- •Writing your First ASP.NET Page
- •Getting Help
- •Summary
- •ASP.NET Basics
- •ASP.NET Page Structure
- •Directives
- •Code Declaration Blocks
- •Comments in VB and C# Code
- •Code Render Blocks
- •ASP.NET Server Controls
- •Server-side Comments
- •Literal Text and HTML Tags
- •View State
- •Working with Directives
- •ASP.NET Languages
- •Visual Basic
- •Summary
- •VB and C# Programming Basics
- •Programming Basics
- •Control Events and Subroutines
- •Page Events
- •Variables and Variable Declaration
- •Arrays
- •Functions
- •Operators
- •Breaking Long Lines of Code
- •Conditional Logic
- •Loops
- •Object Oriented Programming Concepts
- •Objects and Classes
- •Properties
- •Methods
- •Classes
- •Constructors
- •Scope
- •Events
- •Understanding Inheritance
- •Objects In .NET
- •Namespaces
- •Using Code-behind Files
- •Summary
- •Constructing ASP.NET Web Pages
- •Web Forms
- •HTML Server Controls
- •Using the HTML Server Controls
- •Web Server Controls
- •Standard Web Server Controls
- •Label
- •Literal
- •TextBox
- •HiddenField
- •Button
- •ImageButton
- •LinkButton
- •HyperLink
- •CheckBox
- •RadioButton
- •Image
- •ImageMap
- •PlaceHolder
- •Panel
- •List Controls
- •DropDownList
- •ListBox
- •RadioButtonList
- •CheckBoxList
- •BulletedList
- •Advanced Controls
- •Calendar
- •AdRotator
- •TreeView
- •SiteMapPath
- •Menu
- •MultiView
- •Wizard
- •FileUpload
- •Web User Controls
- •Creating a Web User Control
- •Using the Web User Control
- •Master Pages
- •Using Cascading Style Sheets (CSS)
- •Types of Styles and Style Sheets
- •Style Properties
- •The CssClass Property
- •Summary
- •Building Web Applications
- •Introducing the Dorknozzle Project
- •Using Visual Web Developer
- •Meeting the Features
- •The Solution Explorer
- •The Web Forms Designer
- •The Code Editor
- •IntelliSense
- •The Toolbox
- •The Properties Window
- •Executing your Project
- •Using Visual Web Developer’s Built-in Web Server
- •Using IIS
- •Using IIS with Visual Web Developer
- •Core Web Application Features
- •Web.config
- •Global.asax
- •Using Application State
- •Working with User Sessions
- •Using the Cache Object
- •Using Cookies
- •Starting the Dorknozzle Project
- •Preparing the Sitemap
- •Using Themes, Skins, and Styles
- •Creating a New Theme Folder
- •Creating a New Style Sheet
- •Styling Web Server Controls
- •Adding a Skin
- •Applying the Theme
- •Building the Master Page
- •Using the Master Page
- •Extending Dorknozzle
- •Debugging and Error Handling
- •Debugging with Visual Web Developer
- •Other Kinds of Errors
- •Custom Errors
- •Handling Exceptions Locally
- •Summary
- •Using the Validation Controls
- •Enforcing Validation on the Server
- •Using Validation Controls
- •RequiredFieldValidator
- •CompareValidator
- •RangeValidator
- •ValidationSummary
- •RegularExpressionValidator
- •Some Useful Regular Expressions
- •CustomValidator
- •Validation Groups
- •Updating Dorknozzle
- •Summary
- •What is a Database?
- •Creating your First Database
- •Creating a New Database Using Visual Web Developer
- •Creating Database Tables
- •Data Types
- •Column Properties
- •Primary Keys
- •Creating the Employees Table
- •Creating the Remaining Tables
- •Executing SQL Scripts
- •Populating the Data Tables
- •Relational Database Design Concepts
- •Foreign Keys
- •Using Database Diagrams
- •Diagrams and Table Relationships
- •One-to-one Relationships
- •One-to-many Relationships
- •Many-to-many Relationships
- •Summary
- •Speaking SQL
- •Reading Data from a Single Table
- •Using the SELECT Statement
- •Selecting Certain Fields
- •Selecting Unique Data with DISTINCT
- •Row Filtering with WHERE
- •Selecting Ranges of Values with BETWEEN
- •Matching Patterns with LIKE
- •Using the IN Operator
- •Sorting Results Using ORDER BY
- •Limiting the Number of Results with TOP
- •Reading Data from Multiple Tables
- •Subqueries
- •Table Joins
- •Expressions and Operators
- •Transact-SQL Functions
- •Arithmetic Functions
- •String Functions
- •Date and Time Functions
- •Working with Groups of Values
- •The COUNT Function
- •Grouping Records Using GROUP BY
- •Filtering Groups Using HAVING
- •The SUM, AVG, MIN, and MAX Functions
- •Updating Existing Data
- •The INSERT Statement
- •The UPDATE Statement
- •The DELETE Statement
- •Stored Procedures
- •Summary
- •Introducing ADO.NET
- •Importing the SqlClient Namespace
- •Defining the Database Connection
- •Preparing the Command
- •Executing the Command
- •Setting up Database Authentication
- •Reading the Data
- •Using Parameters with Queries
- •Bulletproofing Data Access Code
- •Using the Repeater Control
- •More Data Binding
- •Inserting Records
- •Updating Records
- •Deleting Records
- •Using Stored Procedures
- •Summary
- •DataList Basics
- •Handling DataList Events
- •Editing DataList Items and Using Templates
- •DataList and Visual Web Developer
- •Styling the DataList
- •Summary
- •Using the GridView Control
- •Customizing the GridView Columns
- •Styling the GridView with Templates, Skins, and CSS
- •Selecting Grid Records
- •Using the DetailsView Control
- •Styling the DetailsView
- •GridView and DetailsView Events
- •Entering Edit Mode
- •Using Templates
- •Updating DetailsView Records
- •Summary
- •Advanced Data Access
- •Using Data Source Controls
- •Binding the GridView to a SqlDataSource
- •Binding the DetailsView to a SqlDataSource
- •Displaying Lists in DetailsView
- •More on SqlDataSource
- •Working with Data Sets and Data Tables
- •What is a Data Set Made From?
- •Binding DataSets to Controls
- •Implementing Paging
- •Storing Data Sets in View State
- •Implementing Sorting
- •Filtering Data
- •Updating a Database from a Modified DataSet
- •Summary
- •Security and User Authentication
- •Basic Security Guidelines
- •Securing ASP.NET 2.0 Applications
- •Working with Forms Authentication
- •Authenticating Users
- •Working with Hard-coded User Accounts
- •Configuring Forms Authentication
- •Configuring Forms Authorization
- •Storing Users in Web.config
- •Hashing Passwords
- •Logging Users Out
- •ASP.NET 2.0 Memberships and Roles
- •Creating the Membership Data Structures
- •Using your Database to Store Membership Data
- •Using the ASP.NET Web Site Configuration Tool
- •Creating Users and Roles
- •Changing Password Strength Requirements
- •Securing your Web Application
- •Using the ASP.NET Login Controls
- •Authenticating Users
- •Customizing User Display
- •Summary
- •Working with Files and Email
- •Writing and Reading Text Files
- •Setting Up Security
- •Writing Content to a Text File
- •Reading Content from a Text File
- •Accessing Directories and Directory Information
- •Working with Directory and File Paths
- •Uploading Files
- •Sending Email with ASP.NET
- •Configuring the SMTP Server
- •Sending a Test Email
- •Creating the Company Newsletter Page
- •Summary
- •The WebControl Class
- •Properties
- •Methods
- •Standard Web Controls
- •AdRotator
- •Properties
- •Events
- •BulletedList
- •Properties
- •Events
- •Button
- •Properties
- •Events
- •Calendar
- •Properties
- •Events
- •CheckBox
- •Properties
- •Events
- •CheckBoxList
- •Properties
- •Events
- •DropDownList
- •Properties
- •Events
- •FileUpload
- •Properties
- •Methods
- •HiddenField
- •Properties
- •HyperLink
- •Properties
- •Image
- •Properties
- •ImageButton
- •Properties
- •Events
- •ImageMap
- •Properties
- •Events
- •Label
- •Properties
- •LinkButton
- •Properties
- •Events
- •ListBox
- •Properties
- •Events
- •Literal
- •Properties
- •MultiView
- •Properties
- •Methods
- •Events
- •Panel
- •Properties
- •PlaceHolder
- •Properties
- •RadioButton
- •Properties
- •Events
- •RadioButtonList
- •Properties
- •Events
- •TextBox
- •Properties
- •Events
- •Properties
- •Validation Controls
- •CompareValidator
- •Properties
- •Methods
- •CustomValidator
- •Methods
- •Events
- •RangeValidator
- •Properties
- •Methods
- •RegularExpressionValidator
- •Properties
- •Methods
- •RequiredFieldValidator
- •Properties
- •Methods
- •ValidationSummary
- •Properties
- •Navigation Web Controls
- •SiteMapPath
- •Properties
- •Methods
- •Events
- •Menu
- •Properties
- •Methods
- •Events
- •TreeView
- •Properties
- •Methods
- •Events
- •HTML Server Controls
- •HtmlAnchor Control
- •Properties
- •Events
- •HtmlButton Control
- •Properties
- •Events
- •HtmlForm Control
- •Properties
- •HtmlGeneric Control
- •Properties
- •HtmlImage Control
- •Properties
- •HtmlInputButton Control
- •Properties
- •Events
- •HtmlInputCheckBox Control
- •Properties
- •Events
- •HtmlInputFile Control
- •Properties
- •HtmlInputHidden Control
- •Properties
- •HtmlInputImage Control
- •Properties
- •Events
- •HtmlInputRadioButton Control
- •Properties
- •Events
- •HtmlInputText Control
- •Properties
- •Events
- •HtmlSelect Control
- •Properties
- •Events
- •HtmlTable Control
- •Properties
- •HtmlTableCell Control
- •Properties
- •HtmlTableRow Control
- •Properties
- •HtmlTextArea Control
- •Properties
- •Events
- •Index
Chapter 12: Advanced Data Access
Data Tables in ADO.NET 2.0
The DataTable object in ADO.NET 2.0 is more powerful than it was in previous incarnations of the technology. It can now be used independently of DataSets when the full power of a DataSet is not required.
A DataSet mirrors the structure of a relational database, as Figure 12.21 shows.
Figure 12.21. The structure of a DataSet closely resembles that of a database
You can see the parallel between the DataSet’s structure and that of a database. A database contains tables; here, the DataSet contains DataTables. Tables in a database have columns and rows; our DataTables have DataColumns and DataRows. When we work in a database, we establish relationships between tables; here, we’d create DataRelations. The major difference between DataSets and databases is that DataSets are memory-resident, while a centralized database resides inside a database management system.
Let’s look at how we can create a DataSet within code.
Binding DataSets to Controls
Now that you have some understanding of the structure of a typical DataSet, let’s look at the process involved in creating a DataSet in code, and binding a DataTable to a control. To illustrate this example, we’ll create a simple page that displays the Dorknozzle departments; we’ll call this page Departments.aspx.
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Binding DataSets to Controls
Create a new web form called Departments.aspx, as you have for the other pages in the Dorknozzle project. Update the generated code like this:
File: Departments.aspx (excerpt)
<%@ Page Language="VB" MasterPageFile="~/DorkNozzle.master" AutoEventWireup="False" CodeFile="Departments.aspx.vb" Inherits="Departments" title="Dorknozzle Departments" %>
<asp:Content ID="Content1" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server">
<h1>Dorknozzle Departments</h1>
<asp:GridView id="departmentsGrid" runat="server"> </asp:GridView>
</asp:Content>
So far, everything looks familiar. We have a blank page based on
Dorknozzle.master, with an empty GridView control called departmentsGrid. Our goal through the rest of this chapter is to learn how to use the DataSet and related objects to give life to the GridView control.
Switch to Design View, and double-click on an empty part of the form to generate the Page_Load event handler. Add references to the System.Data.SqlClient namespace (which contains the SqlDataAdapter class), and, if you’re using VB, the System.Data namespace (which contains classes such as DataSet, DataTable, and so on) and the System.Configuration namespace (which contains the ConfigurationManager class, used for reading connection strings from
Web.config).
Visual Basic |
File: Departments.aspx.vb (excerpt) |
Imports System.Data.SqlClient
Imports System.Data
Imports System.Configuration
Partial Class Departments Inherits System.Web.UI.Page
Protected Sub Page_Load(ByVal sender As Object, _ ByVal e As System.EventArgs) Handles Me.Load
End Sub End Class
C# |
File: Departments.aspx.cs (excerpt) |
using System; |
|
using System.Data; |
|
using System.Configuration; |
|
using System.Collections; |
|
|
|
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Chapter 12: Advanced Data Access
using System.Web;
using System.Web.Security; using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts; using System.Web.UI.HtmlControls;
using System.Data.SqlClient;
public partial class Departments : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
}
Next, we’ll add a method called BindGrid, which populates the GridView control using an SqlDataAdapter and a DataSet. We’ll call BindGrid from Page_Load only when the page is loaded for the first time. We assume that any postback events won’t affect the data that’s to be displayed by the grid, so we populate the grid just once, when the page loads.
Visual Basic File: Departments.aspx.vb (excerpt)
Protected Sub Page_Load(ByVal sender As Object, _ ByVal e As System.EventArgs) Handles Me.Load
If Not Page.IsPostBack Then BindGrid()
End If End Sub
Private Sub BindGrid() ' Define data objects
Dim conn As SqlConnection Dim dataSet As New DataSet
Dim adapter As SqlDataAdapter
'Read the connection string from Web.config Dim connectionString As String = _
ConfigurationManager.ConnectionStrings( _ "Dorknozzle").ConnectionString
'Initialize connection
conn = New SqlConnection(connectionString) ' Create adapter
adapter = New SqlDataAdapter( _
"SELECT DepartmentID, Department FROM Departments", _ conn)
' Fill the DataSet adapter.Fill(dataSet, "Departments")
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Binding DataSets to Controls
' Bind the grid to the DataSet departmentsGrid.DataSource = dataSet departmentsGrid.DataBind()
End Sub
C# |
File: Departments.aspx.cs (excerpt) |
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
BindGrid();
}
}
private void BindGrid()
{
//Define data objects SqlConnection conn;
DataSet dataSet = new DataSet(); SqlDataAdapter adapter;
//Read the connection string from Web.config string connectionString =
ConfigurationManager.ConnectionStrings[
"Dorknozzle"].ConnectionString;
//Initialize connection
conn = new SqlConnection(connectionString); // Create adapter
adapter = new SqlDataAdapter(
"SELECT DepartmentID, Department FROM Departments", conn);
//Fill the DataSet adapter.Fill(dataSet, "Departments");
//Bind the grid to the DataSet departmentsGrid.DataSource = dataSet; departmentsGrid.DataBind();
}
Execute the project, and browse to your departments page, as shown in Figure 12.22.
The grid is already styled, because we have a GridView skin in place. At this point, we’ve achieved a level of functionality that you might otherwise have reached using SqlCommand and SqlDataReader, or the SqlDataSource; the difference is that, this time, we’ve used an SqlDataAdapter and a DataSet.
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Chapter 12: Advanced Data Access
Figure 12.22. The Departments page
An SqlDataAdapter object is created in much the same way as an SqlCommand object. We simply provide it with an SQL statement and an SqlConnection object. However, it’s the line that immediately follows the creation of the adapter that does all the work. The Fill method of the SqlDataAdapter fills our DataSet with the data returned by the SQL query. The Fill method accepts two parameters: the first is the DataSet object that needs to be filled, the second is the name of the table that we want to create within the DataSet.
Once the DataSet has been filled with data, it’s simply a matter of binding the DataSet to the GridView, which we do using the same approach we’d use to bind an SqlDataReader.
Moving on, let’s see how we can add another DataTable to our DataSet. The following code uses the SelectCommand property of the SqlDataAdapter object to create a new command on the fly, and fill the same DataSet with a new
DataTable called Employees:
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Binding DataSets to Controls
Visual Basic
' Create adapter
adapter = New SqlDataAdapter( _
"SELECT DepartmentID, Department FROM Departments", conn)
'Fill the DataSet adapter.Fill(dataSet, "Departments")
'Initialize the adapter with a new command adapter.SelectCommand = New SqlCommand(_
"SELECT EmployeeID, Name, MobilePhone FROM Employees", conn)
'Add the new table to the DataSet
adapter.Fill(dataSet, "Employees")
' Bind the grid to the DataSet departmentsGrid.DataSource = dataSet departmentsGrid.DataMember = "Employees" departmentsGrid.DataBind()
C#
// Create adapter
adapter = new SqlDataAdapter(
"SELECT DepartmentID, Department FROM Departments", conn);
//Fill the DataSet adapter.Fill(dataSet, "Departments");
//Initialize the adapter with a new command adapter.SelectCommand = new SqlCommand(
"SELECT EmployeeID, Name, MobilePhone FROM Employees", conn);
//Add the new table to the DataSet
adapter.Fill(dataSet, "Employees");
// Bind the grid to the DataSet departmentsGrid.DataSource = dataSet; departmentsGrid.DataMember = "Employees"; departmentsGrid.DataBind();
This code binds the Employees table of the DataSet to the GridView control by setting the GridView’s DataMember property. The GridView would now appear as shown in Figure 12.23.
Figure 12.23. Displaying data from a DataTable in a GridView
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