ADONET Training

Technology Solutions Lab Confidential and Proprietary

Data Management

ADO.NET

Data Management

ADO.NET

Technology Solutions Lab 2Confidential and Proprietary

AgendaAgenda

•Introduction to ADO.NET

•Programming with ADO.NET

•DAAB

•Session Summary


Introduction to ADO.NETIntroduction to ADO.NET

•Natural Evolution of ADO

•Interoperability – Based on standards like XML, XSD

•Scalability– Targets distributed, disconnected web scenarios

•High-performance design– Optimized providers and Objects

What is ADO.NET?What is ADO.NET?



DataReaderDataReader

DataAdapterDataAdapter

DataSetDataSet

CommandCommand CommandCommand

ConnectionConnectionConnectionConnection

RecordSetRecordSet

ADO ADO ADO .NET ADO .NET


Introduction to ADO.NETIntroduction to ADO.NETADO.NET and the .NET FrameworkADO.NET and the .NET Framework

Microsoft .NET Framework

Common Language Runtime

Base Classes

Web Services User Interface

Data and XML

ADO.NET XML ... ...



Managed ProviderManaged Provider

DataReaderDataReader

CommandCommandConnectionConnection

SyncSync

Controls,Controls,Designers,Designers,

Code-gen, etcCode-gen, etc

DataSetDataSet

XmlReaderXmlReader

XmlText-XmlText-ReaderReader

XmlNode-XmlNode-ReaderReader

XSL/T, X-Path,XSL/T, X-Path,Validation, etcValidation, etc

XmlData-XmlData-DocumentDocument


Managed Data OverviewManaged Data Overview



Business TierBusiness Tier Data TierData Tier

Windows Forms

Web Forms

Business to Business

Data Object (Class)

DataSet

DataSetDataSet

InternetInternetIntranetIntranet

Data AdapterData Adapter

Data AdapterData Adapter

(BizTalk, for example)

XML

ADO.NET in action…ADO.NET in action…



•System.Data.SqlClient. Contains the SQL Server .NET Data Provider types.

•System.Data.OracleClient. Contains the Oracle .NET Data Provider types

•System.Data.OleDb. Contains the OLE DB .NET Data Provider types.

•System.Data.Odbc. Contains the ODBC .NET Data Provider types.

•System.Data. Contains provider-independent types such as the DataSet and DataTable.

Namespace OrganizationNamespace Organization


Introduction to ADO.NETIntroduction to ADO.NETData access stackData access stack


AgendaAgenda



•DAAB

•Session Summary


Programming with ADO.NETProgramming with ADO.NETManaged Data ProvidersManaged Data Providers

•ADO.NET relies on the services of .NET data providers

–SQL Server .NET Data Provider

–Oracle .NET Data Provider

–OLE DB .NET Data Provider

–ODBC .NET Data Provider

–Managed provider for retrieving XML from SQL Server 2000 (refer:http://msdn.microsoft.com/library/default.asp?url=/nhp/default.asp?contentid=28001300)

•NET Data Provider Object Model–Connection

–Command

–DataReader :Like a recordset but Forward only and read only

–DataAdapter: Transfers data between Database and Dataset


Programming with ADO.NETProgramming with ADO.NET

•Represents A Connection To The Data Source

•On A Connection, You Can…– Represent a unique session with a data source– Create, open, close a connection to a data source

ChangeDatabase, Connection pooling

– Create a Command object associated with the connection

CreateCommand

– Begin, commit, and abort transactions

•Equivalent To The ADODB.Connection Object

ConnectionConnection


Programming with ADO.NETProgramming with ADO.NET

•Example://Specify the System.Data.SQL Namespace//using System.Data.SqlClient

//Create an instance of an SqlConnection objectSqlConnection cnn = new SqlConnection();//Set the connection stringcnn.ConnectionString = "Data Source=.;Initial

Catalog=Northwind;Integrated Security=SSPI";

//Open the Connectioncnn.Open();

ConnectionConnection


•Connection Pooling Example:IDbConnection conn = new SqlConnection();conn.ConnectionString = “Integrated Security=SSPI; Initial

Catalog=Northwind”conn.Open(); // Pool A is created;

IDbConnection conn = new SqlConnection();conn.ConnectionString = “Integrated Security=SSPI; Initial

Catalog=pubs”conn.Open(); // Pool B is created because connection

string is different

IDbConnection conn = new SqlConnection();conn.ConnectionString = “Integrated Security=SSPI; Initial

Catalog=Northwind”conn.Open(); // Uses Pool A

Programming with ADO.NETProgramming with ADO.NETConnectionConnection


•Represents a query to execute on the data source– May be a SQL statement or stored procedure

•Properties of Interest:– Connection: Get or set the data source connection– CommandText: Get or set the query (text) command

A SQL statement or the name of the stored procedure

– CommandType: Get/set how the command is interpreted

Text, StoredProcedure, or TableDirectNote: TableDirect is only supported by the .NET

Framework Data Provider for OLE DB.

– CommandTimeout: The seconds until connection timeout

Programming with ADO.NETProgramming with ADO.NETCommandCommand


•Forward-only data access•“Lightweight” programming model

– Less overhead than using DataAdapter

•Instantiated & returned by Command.ExecuteReader

•Ties up the Command until it is finished reading

•Allows Strongly-Typed Access– Example: GetDateTime, GetDouble, GetGuid,

GetInt32•Properties of Interest:

– FieldCount: Returns the number of fields in the result set– RecordsAffected: Number of affected records

Is not set until all rows are read and you close the DataReader

The number of rows changed, inserted, or deleted; 0 if no rows were affected or the statement failed; and -1 for SELECT statements.

IsClosed and RecordsAffected are the only properties that you can call after the DataReader is closed.

Programming with ADO.NETProgramming with ADO.NETDataReaderDataReader


•Methods to retrieve data:– By column type and/or index: GetValue; GetString; etc.– Read(): Advances reader to next record– NextResult(): Advanced to next result set in batch– GetValues(): Gets the current row

Programming with ADO.NETProgramming with ADO.NETDataReaderDataReader


// Code for creating the OleDbConnection “adoConn” not shownString myQuery = “SELECT * FROM Customers”;adoConn.Open();OleDbCommand myCmd = new OleDbCommand( myQuery,adoConn );

// Declare the OleDbDataReader & // then instantiate it with ExecuteReader(...) ...OleDbDataReader reader = myCmd.ExecuteReader();

// Always call Read before accessing data. while( reader.Read() )

{ Object [] cols = new Object[10] ;

reader.GetValues( cols ); Console.WriteLine( cols[0].ToString() + " | " + cols[1] );}

// Always Close the reader and the connection when donereader.Close();adoConn.Close();

Programming with ADO.NETProgramming with ADO.NETDataReader: ExampleDataReader: Example


•Bridge between the DataSet and the data store•Means to modify the DataSet and data source

Programming with ADO.NETProgramming with ADO.NETDataAdapterDataAdapter


SelectCommandSelectCommand

InsertCommandInsertCommand

UpdateCommandUpdateCommand

DeleteCommandDeleteCommand

TableMappingsTableMappings

Data storeData store

DataSetDataSet


•RowUpdated, RowUpdating event handlers ptovides facility to access the row before updating and after updating

•MissingMappingAction– Determines the action to take when incoming

data does not have a matching table or columnPassthrough, Ignore, Error

•MissingSchemaAction – Determines the action to take when existing

DataSet schema does not match incoming data.Add, AddWithKey, Ignore, Error

Programming with ADO.NETProgramming with ADO.NETDataAdapterDataAdapter


•In memory store for client data

•Relational view of data– Tables, Columns, Rows– Constraints, Relations

•Persist Data And Schema As XML

•Explicit Disconnected Model– Disconnected, remotable object

Programming with ADO.NETProgramming with ADO.NETDataSetDataSet

RelationRelation

RowRow

ConstraintConstraint

ColumnColumn

TableTable

ColumnsColumns

ConstraintsConstraints

RowsRows

DataSetDataSet

TablesTables

RelationsRelations


DataSet Tables

DataTable

Relations

DataRelation

DataRelationDataTable

DataTable

DataView

DataViewManager

DataRow(s)

DataColumn

Constraint(s)

Programming with ADO.NETProgramming with ADO.NETDataSetDataSet


Extracts tablesExtracts tablesWith ManagedWith Managed

ProviderProvider

Resolves changesResolves changeswith Managedwith ManagedProviderProvider

Makes changesMakes changesto datato data

Sets upSets uprelationshipsrelationships

OriginalDataStore

DataSet

Table1

Table2

DataSet

Table1

Table2

DataSet

Table1

Table2

Programming with ADO.NETProgramming with ADO.NETDataSet Life cycleDataSet Life cycle

ConnectedConnectedOperationsOperations

DisconnectedDisconnectedOperationsOperations


•May be mapped to a physical table in the data source

•Can be related to one another through DataRelations

•Optimistic concurrency or locking - model•Properties of Interest:

– Columns: Returns ColumnsCollection of DataColumns– Rows: Returns DataRow objects as a RowsCollection– ParentRelations: Returns the RelationsCollection– Constraints: Returns the table’s

ConstraintsCollection– DataSet: Returns the DataSet of the DataTable – PrimaryKey: Gets the DataColumns that make up

the table’s primary key

Programming with ADO.NETProgramming with ADO.NETDataSet DataSet DataTable DataTable


DataSet ds = new DataSet();

// Create DataTable object: “Customers”.DataTable dt= new DataTable( “Customers” );

// Create and add columns to the table // 1. Explicitly create and Add a DataColumnDataColumn dc; dc = new DataColumn( “CustID”,

Type.GetType("System.Int16"));dt.Columns.Add( dc );

// 2. Implicitly Create and Add columns (DataColumn).dt.Columns.Add( “First_Name”,Type.GetType("System

String”));dt.Columns.Add( “Last_Name”, Type.GetType("System

String”));

// Add the DataTable object to the DataSetds.Tables.Add( dt );

Programming with ADO.NETProgramming with ADO.NETDataSet DataSet DataTable Example DataTable Example

•Create a DataTable and add it to a DataSet


SqlConnection nwindConn = new SqlConnection("Data Source=localhost;Integrated Security=SSPI;Initial Catalog=northwind");

SqlDataAdapter custDA = new SqlDataAdapter("SELECT CustomerID, CompanyName FROM Customers ORDER BY CustomerID", nwindConn);

// The Update command checks for optimistic concurrency violations in the WHERE clause. custDA.UpdateCommand = new SqlCommand("UPDATE Customers (CustomerID, CompanyName)

VALUES(@CustomerID, @CompanyName) " + "WHERE CustomerID = @oldCustomerID AND CompanyName = @oldCompanyName",

nwindConn); custDA.UpdateCommand.Parameters.Add("@CustomerID", SqlDbType.NChar, 5, "CustomerID"); custDA.UpdateCommand.Parameters.Add("@CompanyName", SqlDbType.NVarChar, 30, "CompanyName"); // Pass the original values to the WHERE clause parameters. SqlParameter myParm; myParm = custDA.UpdateCommand.Parameters.Add("@oldCustomerID", SqlDbType.NChar, 5, "CustomerID"); myParm.SourceVersion = DataRowVersion.Original; myParm = custDA.UpdateCommand.Parameters.Add("@oldCompanyName", SqlDbType.NVarChar, 30,

"CompanyName"); myParm.SourceVersion = DataRowVersion.Original; // Add the RowUpdated event handler. custDA.RowUpdated += new SqlRowUpdatedEventHandler(OnRowUpdated); DataSet custDS = new DataSet(); custDA.Fill(custDS, "Customers"); // Modify the DataSet contents. custDA.Update(custDS, "Customers"); foreach (DataRow myRow in custDS.Tables["Customers"].Rows) { if (myRow.HasErrors) Console.WriteLine(myRow[0] + "\n" + myRow.RowError); }protected static void OnRowUpdated(object sender, SqlRowUpdatedEventArgs args){ if (args.RecordsAffected == 0) { args.Row.RowError = "Optimistic Concurrency Violation Encountered"; args.Status = UpdateStatus.SkipCurrentRow; }}

Programming with ADO.NETProgramming with ADO.NETDataSet DataSet Optimistic concurrency Example Optimistic concurrency Example


•Used to create logical relations between your data– Create relations between two (2) DataTable

objects– Requires a DataColumn object from each DataTable– The DataType of both DataColumns must be the

sameCannot relate a Int32 DataColumn and a String

DataColumn– The relation is named (by you!)

DataRelation dr=new DataRelation( “myRelation”,...)

•RelationsCollection used to hold/group them– Accessed through the DataSet’s Relations property

Programming with ADO.NETProgramming with ADO.NETDataSet DataSet DataTable Relations:DataRelation object DataTable Relations:DataRelation object


// Building on the DataTable example earlier... // Get the DataTable DataColumns we want to relate...

DataColumn parentCol, childCol;parentCol=

DataSet.Tables["Customers"].Columns["CustID"];childCol = DataSet.Tables["Orders“].Columns["CustID"];

// Create DataRelation with the name “CustomerOrders”...

DataRelation dr = new DataRelation("CustomersOrders", parentCol, childCol);

// Add the relation to the DataSet... ds.Relations.Add( dr );

Programming with ADO.NETProgramming with ADO.NETDataSet DataSet DataTable Relations:DataRelation object DataTable Relations:DataRelation object

•Example


•DataSet can read/write XML for its data and/or schema– You can create or modify data in a DataSet using XML– You can create or modify the DataSets schema using XML

•XML-related DataSet methods for reading:– ReadXml: Reads an XML schema and data into the DataSet– ReadXmlSchema: Reads an XML schema into the DataSet

•And for writing: – WriteXml, WriteXmlSchema– GetXml, GetXmlSchema

•Namespace property: – The Namespace property is used when reading and writing

an XML document into the DataSet

•Full support for DiffGrams– A DiffGram is an XML format that is used to identify

current and original versions of data elements

Programming with ADO.NETProgramming with ADO.NETDataSet and XMLDataSet and XML


// Code for creating the DataSet mds and loading the // DataSet from a data source not shown.

String oFile = “C:\\My_ADO.NET\\myXmlOutput.xsd”;String iFile = “C:\\My_ADO.NET\\myXmlInput.xml”; // Write the DataSet’s XMLSchema to an XML Documentmds.WriteXmlSchema( oFile );

// Read/Upload XML Data into the DataSetmds.ReadXml( iFile);

// modify the data // ...

// Write the existing Data to an XML Documentmds.WriteXml( "C:\\My_ADO.NET\\myXmlData.xml",

XmlWriteMode.DiffGram);

Programming with ADO.NETProgramming with ADO.NETDataSet and XML: ExampleDataSet and XML: Example


•Exposes relational view over structured XML

•Allows strong typing, control binding, relational access of XML data

•Allows XML tools (schema validation, XSL/T, XPath queries) against relational data

•Preserves full fidelity of XML Document

Programming with ADO.NETProgramming with ADO.NETDataSet and XmlDataDocumentDataSet and XmlDataDocument


Programming with ADO.NETProgramming with ADO.NETDataSet and XmlDataDocumentDataSet and XmlDataDocument


// Associate an XmlDataDocument with the DataSetXmlDataDocument xmlDocument = new XmlDataDocument(pubs);

// Get an XmlNavigator for the XmlDataDocumentDataDocumentNavigator xmlNavigator = new

DataDocumentNavigator(xmlDocument);

// Get all the authors from CAxmlNavigator.Select("//Authors[state='CA']/au_lname");

// Write out all of the authors' last nameswhile(xmlNavigator.MoveToNextSelected()){

Console.WriteLine("Name = " + xmlNavigator.InnerText);}

//As usual, you can navigate the data using the DataSet

DataRow row;foreach(row in xmlDocument .DataSet.Tables[0].Rows) {

Console.WriteLine(row[1]) ; //prints au_lname}

Programming with ADO.NETProgramming with ADO.NETDataSet and XmlDataDocument : ExampleDataSet and XmlDataDocument : Example


•Populate DataSet with XML DocumentDataSet RegionDS = new DataSet();

RegionDS.ReadXmlSchema( "Region_More.XSD" ); XmlDataDocument DataDoc = new XmlDataDocument( RegionDS ); DataDoc.Load("Region_More.XML" );

//Now RegionDS contains data loaded from XML file

Programming with ADO.NETProgramming with ADO.NETDataSet and XmlDataDocument : ExampleDataSet and XmlDataDocument : Example


DataViewManagerDataViewSettings

DataSet Tables

DataTable

Relations

DataRelation

DataRelationDataTable

DataTable

DataView

DataViewSetting

DataViewSetting

DataRow(s)

DataColumn

Constraint(s)

Programming with ADO.NETProgramming with ADO.NETDataViewsDataViews


•Create multiple views on DataTable objects

•Bindable to user interface controls

•Properties of Interest:– Table: Retrieves or sets the associated DataTable

– Sort: Gets or sets the table’s sort columns and sort order

– RowFilter: Gets or sets the expression used to filter rows

– RowStateFilter: Gets or sets the row state filterNone, Unchanged, New, Deleted, ModifiedCurrent, and

others

Programming with ADO.NETProgramming with ADO.NETDataViews: Viewing DataDataViews: Viewing Data


// Code for myTable “Customers” with “Name” column not shown

DataView view1 = new DataView( myTable );DataView view2 = new DataView( myTable );

// Creates Ascending view of Customers by “Name”view1.Sort = “Name ASC”;

// Set the view to show only modified (original) rows view2.RowStateFilter= DataViewRowState.ModifiedOriginal;

// Bind to UI element(s)... DataGrid myGrid = new DataGrid();myGrid.SetDataBinding( view1, “Customer”);

//...

Programming with ADO.NETProgramming with ADO.NETDataViews: Viewing Data: ExampleDataViews: Viewing Data: Example


•Similar to a DataView but DataSet oriented•Used to create multiple views on a DataSet

– Ability to automatically set filters on the tables

•Properties of Interest:– DataViewSettings: Gets the DataView for on each

DataTable– DataSet: Gets or sets the DataSet to be viewed

•CreateDataView method– Creates a DataView on a DataTable

Programming with ADO.NETProgramming with ADO.NETDataViews: Viewing More Data : DataViewManagerDataViews: Viewing More Data : DataViewManager


// Create the DataViewManager & views...DataViewManager dvMgr = new DataViewManager( myDS );dvMgr.CreateDataView( ds.Tables[“Orders"] );dvMgr.DataViewSettings[“Orders"].Sort = “CustID ASC";

dvMgr.CreateDataView( ds.Tables[“Customers"] );dvMgr.DataViewSettings[“Customers"].Sort = “Name DESC";

// Bind to a UI elements/controls...dataGrid1.DataSource = viewMgr;dataGrid1.DataMember = "Table1";

dataGrid2.DataSource = viewMgr;dataGrid2.DataMember = "Table2";

// Update the control with the data...dataGrid1.Update();dataGrid2.Update();

Programming with ADO.NETProgramming with ADO.NETDataViews: DataViewManager : ExampleDataViews: DataViewManager : Example


1. adpter.Fill(ds,startrecord, maxrecords,sourceTableName)

2. switch (direction) //Next, Previous { case "Next": selCmd.CommandText = "SELECT TOP " + pageSize + " CustomerID, CompanyName FROM

Customers " + "WHERE CustomerID > @CustomerId ORDER BY CustomerID"; selCmd.Parameters.Add("@CustomerId", SqlDbType.VarChar, 5).Value =

lastVisibleCustomer; break; case "Previous": selCmd.CommandText = "SELECT TOP " + pageSize + " CustomerID, CompanyName FROM

Customers " + "WHERE CustomerID < @CustomerId ORDER BY CustomerID DESC"; selCmd.Parameters.Add("@CustomerId", SqlDbType.VarChar, 5).Value =

firstVisibleCustomer; break; default: selCmd.CommandText = "SELECT TOP " + pageSize + " CustomerID, CompanyName FROM

Customers ORDER BY CustomerID"; // Determine total pages. SqlCommand totCMD = new SqlCommand("SELECT Count(*) FROM Customers", nwindConn); nwindConn.Open(); int totalRecords = (int)totCMD.ExecuteScalar(); nwindConn.Close(); totalPages = (int)Math.Ceiling((double)totalRecords / pageSize);

break; }

Programming with ADO.NETProgramming with ADO.NETPaging: ExamplesPaging: Examples


AgendaAgenda



•DAAB

•Session Summary


DAABDAAB


•SqlHelper class – provides a set of static methods that you can use to

execute a variety of different command types against a SQL Server database.

•SqlHelperParameterCache class – provides command parameter caching functionality

used to improve performance. This is used internally by a number of the Execute methods (specifically, the overloads that are designed to execute only stored procedures). It can also be used directly by the data access client to cache specific parameter sets for specific commands.

– Uses sp_procedure_params_rowset procedure

•URL: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnbda/html/daab-rm.asp

DAABDAAB


AgendaAgenda



•DAAB

•Session Summary


User / Browser

IIS

DataAccess

Database

Base C

omponents

BusinessRules

EA

F

Web

ASP.NET

DAL1

DAAB

ADO.NET

Session SummarySession SummaryBflex applications Architecture OverviewBflex applications Architecture Overview


Session SummarySession Summary

•A natural evolution of ADO•Designed to work with XML•Closely integrated with the .NET

Framework•Provides fast and efficient mechanisms for

connected and disconnected data access

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