1. ADO.NET

2. Objectives Introduce Microsoft® ADO.NET Show the evolution of ADO to ADO.NET Introduce the primary components of ADO.NET

3. Contents Differences Between ADO and ADO.NET Benefits of ADO.NET ADO.NET Core Concepts and Architecture The ADO.NET Object Model The DataSet and Data Views Managed Providers

4. ADO.NET and the.NET Framework Microsoft.NET Framework Common Language Runtime Base Classes Web ServicesUser Interface Data and XML ADO.NET XML...

5. ADO vs. ADO.NET 1/2 ADO Designed for connected access Tied to the physical data model The RecordSet is the central data container RecordSet is one (1) table that contains all the data Retrieving data from > 1 table or source requires a database JOIN Data is “flattened”: lose relationships; navigation is sequential Data types are bound to COM/COM+ data types Data sharing via COM marshalling Problems marshalling through firewalls (DCOM, binary)

6. ADO vs. ADO.NET 2/2 ADO.NET Designed for disconnected access Can model data logically! The DataSet replaces the RecordSet DataSet can contain multiple tables Retrieving data from > 1 table or source does not require a JOIN Relationships are preserved: navigation is relational Data types are only bound to XML schema No data type conversions required XML, like HTML, is plaintext: “Firewall friendly”

7. Benefits of ADO.NET Interoperability through use of XML (more later!) Open standard for data that describes itself Human readable and decipherable text Used internally but accessible externally Can use XML to read and write and move data Scalability through the disconnected DataSet Connections are not maintained for long periods Database locking does not occur Locking support with ServiceComponents Optimistic locking otherwise Works the way the Web works: “Hit and Run!” Maintainability Separation of data logic and user interface

8. Visual Studio.NET Enhancements Typed programming—a programming style Uses end-user words: Easier to read and write Statement completion in Microsoft Visual Studio.NET Safer: Provides compile-time checking Examples: Untyped: Table("Customer")("Jones").Column(“Balance”) Typed: myDataSet.Customer("Jones").Balance Wizard support Generates queries for you Graphical way to select data you want to work with XML Designer (for creating DataSets)

9. Core Concepts and Architecture The ADO.NET Object Model Objects of System.Data.NET data providers ADO.NET namespace hierarchy Organizes the object model Includes: System.Data System.Data.OleDb System.Data.Common System.Data.SqlClient System.Data.SqlTypes

10. ADO.NET ADO.NET-related Namespaces System.Data.OleDb.SqlClient.SqlTypes.Common

11. System.Data Namespace Contains the basis and bulk of ADO.NET Data-centric namespace Provides the means to work on and with your data! Classes and methods to manipulate your data Ability to create views of your data Means to logically represent your data Enables the use of XML to view, share, and store data

12. Introducing the Objects… Contains the “main” classes of ADO.NET In-memory cache of data In-memory cache of a database table Used to manipulate a row in a DataTable Used to define the columns in a DataTable Used to relate 2 DataTables to each other Used to create views on DataSets System.Data DataTable DataRow DataRelation DataColumn DataViewManager DataSet

13. Tables DataTable Putting the Objects Together… Relations DataRelation DataRow(s) DataColumn Constraint(s) DataTable DataView DataViewManager

14. Working Data - The DataSet An in-memory cache of data from a data source Common way to represent and manipulate data Universal data container Not just for use with databases Logical or physical representation of data Designed to be disconnected from the data source Connect, execute query, disconnect Can use XML To read and write data To read and write XMLSchema

15. Properties & Methods of Interest Collections are used to add & remove tables & relations Properties of Interest: Tables: Returns the collection of DataTable objects Relations: Returns the collection of DataRelations Namespace: Gets or sets the namespace of the DataSet Using Properties Samples: myDataSet.Tables.Add( myTable ); myDataTableCollection = myDataSet.Tables

16. All About Data! Universal Data Container DataSet: It’s not just for Databases

17. The DataTable 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

18. System.Data—DataSet and DataTable Create a DataTable and add it to a DataSet 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 DataColumn DataColumn 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 DataSet ds.Tables.Add( dt );

19. Relating Data - The DataRelation 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 same Cannot relate a Int32 DataColumn and a String DataColumn The relation is named (by you!) DataRelation dr=new DataRelation( “myRelation”,...) Makes relational navigation possible RelationsCollection used to hold/group them Accessed through the DataSet’s Relations property

20. Creating Relations With DataRelations // 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 );

21. XML and the DataSet 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: sets the namespace for serialization Full support for SQL Server-style DiffGrams

22. Methods of Reading and Writing 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.xsd”; // Write the DataSet’s XMLSchema to an XML Document mds.WriteXmlSchema( oFile ); // Read/Upload XML Data into the DataSet mds.ReadXml( iFile); // modify the data //... // Write the existing Data to an XML Document mds.WriteXml( "C:\\My_ADO.NET\\myXmlData.txt", XmlWriteMode.DiffGram);

23. DataViewManager DataViewSettings DataSet Tables DataTable DataSet, DataRelation, Data…Views Relations DataRelation DataRow(s) DataColumn Constraint(s) DataTable DataView DataViewSetting

24. Viewing Data - The DataView 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 filter None, Unchanged, New, Deleted, ModifiedCurrent, and others

25. Creating a DataView by Example // 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”); //...

26. Viewing More Data - DataViewManager 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

27. DataViewManager By Example // 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();

28. The (ADO).NET Data Providers A collection of classes for accessing data sources: Microsoft SQL Server™ 2000, SQL Server 7, and MSDE Any OLE Database (OLE DB) providers Including: Oracle, JET, and SQL OLE DB Providers Establish connection between DataSets and data stores Two.NET data providers: ADO: via the System.Data.OleDb namespace SQL Server: via the System.Data.SqlClient namespace System.Data.OleDb is the.NET data provider

29. .NET Data Providers Hierarchy System.Data.OleDb.SqlClient OleDbCommand OleDbConnection OleDbDataReader OleDbDataAdapter SqlCommand SqlConnection SqlDataReader SqlDataAdapter.Common Contains classes shared by both

30. OleDbConnection and SqlConnection Represent a unique session with a data source Create, open, close a connection to a data source Functionality and methods to perform transactions OleDbConnection example: String conStr="Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=NWIND_RW.MDB"; OleDbConnection aConn = new OleDbConnection(conStr); aConn.Open(); // Execute Queries using OleDbDataAdapter Class aConn.Close();

31. OleDbDataAdapter Class 1/2 Bridge between the DataSet and the data store Inherited from the DataAdapter class Means to modify the DataSet and data source data store DataSet DataAdapter

32. OleDbDataAdapter Class 2/2 Properties of Interest: DeleteCommand: The delete command expressed in SQL InsertCommand: Gets or sets insert command SelectCommand: Gets or sets select command UpdateCommand: Gets or sets update command TableMappings: Maps source table and a DataTable OleDbCommands retrieved or set by command properties Implements abstract methods of the DataAdapter class: public abstract int Fill( DataSet dataSet ); public abstract int Update( DataSet dataSet );

33. OleDbCommand Class 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 TableDirect CommandTimeout: The seconds until connection timeout

34. OleDbDataReader 1/2 Forward-only data access “Lightweight” programming model Less overhead than using OleDbDataAdapter Instantiated & returned by OleDbCommand. ExecuteReader Ties up the OleDbCommand until it is finished reading

35. OleDbDataReader 2/2 Properties of Interest: FieldCount: Returns the number of fields in the result set RecordsAffected : Number of affected records 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

36. OleDbDataReader Sample // Code for creating the OleDbConnection “adoConn” not shown String 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 done reader.Close(); adoConn.Close();

37. Summary ADO.NET is the evolution of ADO It is a disconnected, Web-centric model Flexible in its ability to work with data Increases your ability to logically organize data Extensive support for XML Facilitates working with and sharing data Interacts with a wide variety of data sources

38. Questions ?

39. Duwamish Books A Sample Application for Microsoft.NET

40. Installing the Sample 1/2 Install the "Enterprise Samples" with Visual Studio.NET Location of the C# Version Visual Studio.NET folder Directory.\EnterpriseSamples\DuwamishOnline CS Location of the Visual Basic® Version Directory.\EnterpriseSamples\DuwamishOnline VB Installation Tasks Check the prerequsites Microsoft Windows® 2000 Server, SQL Server 2000 with English Query optional and supported Read the Readme.htm Run Installer Duwamish.msi (double-click it)

41. Installing the Sample 2/2 The installation wizard will guide you Defaults should be OK for almost everybody Setup will install database, Web site, and code After installation is complete: File/Open Solution with the Duwamish.sln file Can build the sample with Build/Build Solution

42. User / Browser IIS Duwamish Architecture Overview DataAccess Database Common.Data BusinessRules BusinessFacade SystemFramework Web ASP.NET ADO.NE T

43. Common Components Duwamish7.Common Contains systems configuration options Contains common data definitions (classes) Namespace Duwamish.Common.Data "Internal" data representation for Book, Category, Customer, OrderData Duwamish7.SystemFramework Diagnostics utilities Pre and post condition checking classes Dynamic configuration In short: Everything that's pure tech and not business code

44. Duwamish7.DataAccess Contains all database-related code Uses ADO.NET architecture Using SQL Server managed provider Shows DataSet, DataSetCommand usage Optimized for performance by using stored procs

45. Duwamish7.BusinessRules Implements all business rules Validation of business objects (for example, Customer EMail) Updating business objects Calculations (Shipping Cost, Taxes) All data access performed through DataAccess

46. Duwamish7.BusinessFacade Implements logical business subsystems CustomerSystem: Profile management OrderSystem: Order management ProductSystem: Catalog Reads data through DataAccess Data validated and updated using BusinessRules BusinessFacade encapsulates all business-related functionality

47. Duwamish7.Web Implements the user interface for Web access Uses ASP.NET architecture Employs Web Forms model Uses code behind forms Manages state Uses custom Web Controls All functionality accessed through BusinessFacade

48. Shop at Duwamish Online.NET Demo: Duwamish in Action

49. Exploring Duwamish ADO.NET Exploring ADO.NET Features in Duwamish

50. Legal Notices Unpublished work.  2001 Microsoft Corporation. All rights reserved. Microsoft, Visual Basic, Visual Studio, and Windows are either registered trademarks or trademarks of Microsoft Corporation in the United States and/or other countries. The names of actual companies and products mentioned herein may be the trademarks of their respective owners.