Module 7: Accessing Data by Using ADO.NET

Module Overview

Overview of Data Access

Reading and Writing Relational Data

Reading and Writing XML Data

Lesson 1: Overview of Data Access

ADO.NET Object Model

XML Data Access

Data Access Namespaces

Choosing a .NET Framework Data Provider

What Are Connected and Disconnected Operations?

Accessing Data by Using the Visual Studio 2005 IDE

Binding Data to Controls

Demonstration: Accessing Data by Using the Visual Studio 2005 IDE

ADO.NET Object Model

ADO.NETADO.NET

Connected model vs. disconnected modelConnected model vs. disconnected model

Data provider interfacesData provider interfaces

Data provider-specific classesData provider-specific classes

SqlConnection

SqlCommand

SqlDataReader

SqlDataAdapter

SqlConnection

SqlCommand

SqlDataReader

SqlDataAdapter

Data provider-independent classesData provider-independent classes

DataSet

DataTable

DataSet

DataTable

XML Data Access

XmlReaderXmlReader11

XmlWriterXmlWriter22

DOMDOM33 XmlDocument

XmlElement

Data Access Namespaces

Namespace Description

System.Data Core ADO.NET architecture

System.Data.Common Shared classes

System.Data.OracleClient Classes for Oracle

System.Data.OleDb Classes for OLE-DB-compatible data sources

System.Data.Odbc Classes for ODBC data sources

System.Data.Sql Core SQL Server classes

System.Data.SqlClientClasses for SQL Server version 7.0 and later

data sources

System.Xml Classes for XML data sources

…

Choosing a .NET Framework Data Provider

Data Provider Database

.NET Framework Data Provider for Microsoft SQL Server

SQL Server 7.0 and later

Microsoft Data Engine (MSDE)

.NET Framework Data Provider for OLE DB

SQL Server (SQLOLEDB)

Oracle (MSDAORA)

Microsoft Jet (Microsoft.Jet.OLEDB.4.0)

.NET Framework Data Provider for ODBC

SQL Server

Microsoft ODBC for Oracle

Microsoft Access Driver (*.mdb)

.NET Framework Data Provider for Oracle Oracle client software version 8.1.7 and later

What Are Connected and Disconnected Operations?

.NET application.NET application

Connected model Disconnected model

Open connection

Run commands

Retrieve results

Close connection

Create DataSet

Manipulate data

AdventureWorks Database

.NET application.NET application

AdventureWorks Database

Open connection

Close connection

Open connection

Close connection

Update tables

DataSet

Accessing Data by Using the Visual Studio 2005 IDE

On the Data menu, click Add New Data Source On the Data menu, click Add New Data Source 11

Define a new database connection Define a new database connection 22

Save the connection string in the app.config fileSave the connection string in the app.config file33

Specify the tables you want in the DataSetSpecify the tables you want in the DataSet44

Specify a name for the DataSetSpecify a name for the DataSet55

Binding Data to Controls

Add a control to a Windows form Add a control to a Windows form 11

Choose the data source for the control Choose the data source for the control 22

Add queries to the table adapter, if necessaryAdd queries to the table adapter, if necessary33

Write code to fill the table in the DataSetWrite code to fill the table in the DataSet44

Write code to save the table in the DataSetWrite code to save the table in the DataSet55

Demonstration: Accessing Data by Using the Visual Studio 2005 IDE

Create a new data source

Add a DataGridView control and set properties

Bind the DataGridView control to a data source

Update the data source query

Add code to save changes to the data on the FormClosed event

Build and run the application

Lab: Accessing Data by Using a DataGridView Control

Exercise 1: Binding Data to Controls in a Form (15 minutes)

Lesson 2: Reading and Writing Relational Data

Connecting to a Data Source

Creating and Running ADO.NET Commands

How to Retrieve Data by Using a Data Reader

What Is a Data Adapter?

How to Fill and Access DataSet Data

How to Save a DataSet to a Database

Guidelines for Secure Coding with ADO.NET

Connecting to a Data Source

.NET Application.NET Application

2. Create a Connection object

3. Call the Open methodto open the connection

4. Call the Close methodto close the connection

DatabaseDatabase1. Import namespaces

Creating and Running ADO.NET Commands

Method Description

ExecuteScalar Executes a query and returns a single result

ExecuteReader Executes a query and retrieves rows from a data source

ExecuteNonQuery Executes a query that performs an action in the database,

and returns the number of rows affected

How to Retrieve Data by Using a Data Reader

Create a connection object Create a connection object 11

Create a command object and specify an SQL query Create a command object and specify an SQL query 22

Open the database connectionOpen the database connection33

Invoke the ExecuteReader method and obtain a data reader objectInvoke the ExecuteReader method and obtain a data reader object44

Use the data reader object to iterate through the result setUse the data reader object to iterate through the result set55

Close the database connectionClose the database connection66

.NET Application.NET Application

Database

What Is a Data Adapter?

DatabaseDataSet

DataAdapter

Fill MethodFill Method

Update MethodUpdate Method

DataTable Object

Invoke Fill method to populate DataSetInvoke Fill method to populate DataSet11

Invoke Update method to merge changesInvoke Update method to merge changes22

Import required namespacesImport required namespaces11

Create a SqlDataAdapter objectCreate a SqlDataAdapter object22

Set the SelectCommand property to an SQL querySet the SelectCommand property to an SQL query33

Create a DataSet objectCreate a DataSet object44

Open the database connectionOpen the database connection55

Invoke the Fill methodInvoke the Fill method66

Close the database connectionClose the database connection77

How to Fill and Access DataSet Data

How to Save a DataSet to a Database

Import required namespacesImport required namespaces

Create a SqlDataAdapter objectCreate a SqlDataAdapter object

Set the command property to an SQL querySet the command property to an SQL query

Create a DataSet objectCreate a DataSet object

Open the database connectionOpen the database connection

Invoke the update methodInvoke the update method

Close the database connectionClose the database connection

11

22

33

44

55

66

77

Do not echo user security credentials when opening a connectionDo not echo user security credentials when opening a connection

Use Windows authentication if possibleUse Windows authentication if possible

Store connection strings in the application configuration fileStore connection strings in the application configuration file

Encrypt connection stringsEncrypt connection strings

Validate user inputValidate user input

Prevent SQL injection attacksPrevent SQL injection attacks

. . .. . .

Guidelines for Secure Coding with ADO.NET

Stored proceduresStored procedures

Lab: Accessing Data by Using ADO.NET Commands

Exercise 1: Creating and Running Simple Commands (30 minutes)

Exercise 2: (OPTIONAL) Creating and Running Query Commands (30 minutes)

Lesson 3: Reading and Writing XML Data

How to Read and Write a DataSet as XML Data

How to Read XML Data by Using XmlReader

How to Write XML Data by Using XmlWriter

How to Process XML Data by Using the Document Object Model

How to Read and Write a DataSet as XML Data

Save a DataSet as XML

DiffGram

IgnoreSchema

WriteSchema

Load XML into a DataSet

Auto

DiffGram

Fragment

IgnoreSchema

InferSchema

InferTypeSchema

ReadSchema

DataSet

How to Read XML Data by Using XmlReader

Create an XmlReaderSettings object Create an XmlReaderSettings object 11

Create an XmlReader object Create an XmlReader object 22

Iterate through the nodes in the XML document Iterate through the nodes in the XML document 33

Retrieve the value of nodes Retrieve the value of nodes 44

Close the document Close the document 55

How to Write XML Data by Using XmlWriter

Create an XmlWriterSettings object Create an XmlWriterSettings object 11

Create an XmlWriter object Create an XmlWriter object 22

Write the start of the XML documentWrite the start of the XML document33

Write nodes to the XML document Write nodes to the XML document 44

Write the end of the XML document Write the end of the XML document 55

How to Process XML Data by Using the Document Object Model

Read the content of XML data Read the content of XML data

Move randomly around the XML document Move randomly around the XML document

Add, modify, clone, and delete content in the XML document Add, modify, clone, and delete content in the XML document

Create a new XML document Create a new XML document

Operations:

DOM:

A standard API for reading and writing XML data A standard API for reading and writing XML data

Node types include: root, element, child element, and attributeNode types include: root, element, child element, and attribute

Lab: Reading and Writing XML Data

Exercise 1: Reading and Writing a DataSet as XML Data (15 minutes)

Lab Discussion

What are the four core data providers in the .NET Framework?

What classes can you use to establish a connection to a SQL Server database?

What are the advantages and disadvantages of connected and disconnected operations?

What are the available options for reading and writing XML data?