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ADO.NET 2.0: Evolution or Revolution. Shawn Wildermuth MVP, MCSD.NET, Author and Speaker. Who I Am. Shawn Wildermuth swildermuth@adoguy.com Independent Consultant INETA Speaker Book Author “Pragmatic ADO.NET” “MCTS Self-Paced Training Kit (Exam 70-536)”
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ADO.NET 2.0: Evolution or Revolution Shawn Wildermuth MVP, MCSD.NET, Author and Speaker
Who I Am • Shawn Wildermuth • swildermuth@adoguy.com • Independent Consultant • INETA Speaker • Book Author • “Pragmatic ADO.NET” • “MCTS Self-Paced Training Kit (Exam 70-536)” • “Prescriptive Data Architectures” - Upcoming • This Presentation can be found at: • http://adoguy.com/presentations
Agenda • Revolution or Evolution? • ADO.NET 2.0 Changes • Provider Model • DataAdapter Enhancements • DataTable Enhancements • DataSet Enhancements • Typed DataSet Enhancements • TableAdapters • ADO.NET Related Topics • System.Transactions • SQL Server 2005 • ASP.NET 2.0 • ADO.Next • Parting Shots
Evolution or Revolution? • Did they change everything? • In ADO->ADO.NET, the world changed • The Data Team Took a Hard Look • Kept What Worked • Fixed What Didn’t
Evolution or Revolution? (2) • Evolution of the Platform • Better Provider Support • Better DataAdapters • First Class DataTables • Performance Improvements for DataSets • New Typed DataSets • New Table Adapters • Better Transaction Support • SQL Server 2005 Integration
Managed Provider Enhancements • Provider Model • ADO.NET v1.1 was based on interfaces • Not enough for provider-agnostic code • Hard to evolve • ADO.NET v2.0 introduces a common API • Abstract base classes instead of interfaces • Better versioning story • Provider factories enabled at the API level • SQL syntax is still back-end specific
Managed Provider Enhancements (2) Db* abstract base classes (e.g. DbConnection) SqlClient OleDb Odbc Oracle Client 3rd Party 3rd Party Db*Base implementation classes • Complete Reworking of Hierarchy IDb* interfaces (e.g. IDbConnection) Provider- independent apps Code to this layer Provider- specific apps Code to this layer
Managed Provider Enhancements (3) • Provider Factories • Can enumerate Managed Providers • Can create a DbProviderFactory from Name • Factory to create common objects DbProviderFactory factory = DbProviderFactories.GetFactory("System.Data.SqlClient"); DbConnection conn = factory.CreateConnection(); DbCommand cmd = factory.CreateCommand(); DbDataReader rdr = cmd.ExecuteReader(); DbDataAdapter da = factory.CreateDataAdapter(); DataSet theSet = new DataSet(); da.Fill(theSet);
Managed Provider Enhancements (4) • Asynchronous Execution • Added BeginXXX, EndXXX to most Executions • BeginExecuteNonQuery, EndExecuteNonQuery • BeginExecuteReader, EndExecuteReader • Only supported on SqlClient so far • Must add “Asynchronous Processing=true” conn = new SqlConnection( "Server=.;database=...;Asynchronous Processing=true"); cmd = conn.CreateCommand(); // ... conn.Open(); cmd.BeginExecuteReader(new AsyncCallback(SomeMethod), this);
DataAdapter Enhancements • Batch Updates • Updates are normally processed one by one • Batching reduces network round-trips • Works inside transactions • Works with SQL Server 7.0, 2000, 2005 • Also available for OracleClient classes DataSet mySet = new DataSet(); SqlDataAdapter da = new SqlDataAdapter(); da.UpdateBatchSize = 100; da.Update(mySet); DataSet mySet = new DataSet(); OracleDataAdapter da = new OracleDataAdapter(); da.UpdateBatchSize = 100; da.Update(mySet);
CommandBuilder Enhancements • Better Concurrency Support • DbCommandBuilder.ConflictOption • CompareAllSearchableValues • CompareRowVersion • OverwriteChanges • Who cares? • Tool builders • Typed DataSets • ASP.NET 2.0 should have but doesn’t • (Still) Don’t use CommandBuilders at runtime
DataTable Enhancements • First Class Support • DataSet operations now available on DataTable: • ReadXml/WriteXml • ReadXmlSchema/WriteXmlSchema • Clear • Clone • Copy • Merge • GetChanges DataTable tbl = new DataTable(); // Fill the table DataTable newTbl = tbl.Clone(); tbl.Merge(newTbl); DataTable changes = tbl.GetChanges();
DataTable Enhancements (2) • First Class Support (continued) • DataTable is now auto-serializable: • Web Service or Remoting Friendly • MarshalByValue still an issue!
DataTable Enhancements (3) • DataSet not Required • DataAdapters • Fill(DataTable) • Update(DataTable) • DataReader • DataTable.Load(DataReader) • Stream from a DataTable • DataTable.GetTableReader()
DataView Enhancements • DataView.ToTable • Creates a new DataTable from a DataView • Supports Distinct and Column Filtering // Returns the distict rows and only // CompanyName and ContactName columns DataTable filtered = view.ToTable(true, "CompanyName", "ContactName");
DataSet Enhancements • Performance and scalability improvements • Internal Indexing of Rows • Inserts and deletes much faster • Updates almost constant • Selects are faster too • Binary Serialization of Contents • V 1.x DataSet always serialized to XML • Binary serialization an option in V 2.0
DataSet Enhancements (2) • More Loading Options • DataAdapter.Fill • DataAdapter.FillLoadOption • LoadOptions.OverwriteChanges • LoadOptions.PreserveChanges • LoadOptions.Upsert DataSet theSet = new DataSet(); SqlDataAdapter da = new SqlDataAdapter("SELECT * FROM Customers", "..."); da.FillLoadOption = LoadOption.OverwriteChanges; da.Fill(theSet, "Customers");
DataSet Enhancements (3) • More Loading Options • DataAdapter.Fill (continued) • AcceptChangesDuringUpdate • Mirrors AcceptChangesDuringFill from 1.x • DataSet.Load • Load from DataReader directly • FillErrorEventHandler to handle loading errors • Also supports LoadOptions
DataSet Enhancements (4) • Stream data From DataSet • DataSet.GetDataReader method • returns a DataTableReader • RowState values are now updateable • DataRow.SetAdded and DataRow.SetModified
DataSet Enhancements (5) • Common Issue • “Invalid Row Index #5” • Causes when row(s) change and DataViews are in use • Use BeginEdit/EndEdit or remove dead DataViews • Introduced with the index optimization • There are official workarounds but no fix yet…
Typed DataSet Enhancements • Completely Changed Environment • Support for Discovery of Relationships • Works across databases • E.g. Oracle, SQL Server, Access, etc. • TableAdapters • Generated Code to Load/Save Tables • By default uses same robust update code as 1.x • No support for batch queries (SELECTs)
Typed DataSet Enhancements (2) • Completely Changed Environment • Partial Classes • Allows for adding code • Can’t override existing implementation • Good place for Load/Save Code
Typed DataSet Enhancements (3) • Concurrency Changes • Supports Changes in CommandBuilder, sort of… • Timestamp concurrency supported • 1.x Style Brute Force works too • Can specify no concurrency
Typed DataSet Enhancements (4) • What’s Wrong? • Microsoft’s RAD solution • Designer is fragile • Tends to make lots of connection strings • Changing Queries can break other queries • No support for multiple tables in one round-trip • Still no support for inheritance • Events are still the main expansion model • No re-use/upgrade model
BulkCopy • INSERTs aren’t fast enough • SqlBulkCopy • High-performance bulk-insert API • DataReader • DataTable
System.Transactions • Great integration • Transparent transaction enlistment • SQL Server 2005 • Transaction promotion • Nice programming model, no performance hit • Also integrated into SQLCLR • SQL Server 2000 • Auto-enlistment requires DTS • Can disable autoenlistment in Connection String • Not as lightweight as 2005
System.Transactions (2) • Example: using (TransactionScope scope = new TransactionScope()) { using (SqlConnection conn = new SqlConnection("...")) using (SqlCommand cmd = conn.CreateCommand()) { conn.Open(); cmd.CommandText = "..."; cmd.ExecuteNonQuery(); cmd.CommandText = "..."; cmd.ExecuteNonQuery(); } }
System.Transactions (3) • Continue to use SqlClient.Transaction • SQL Server only transactions • When you know they will never change
SQL Server 2005 • New Data Types • Fully integrated in client and server • XML data-type • XML as a first-class language in the server • Query XML data using XQuery • User-defined types • Extend the scalar server type-system using your own CLR types • “MAX” types • Use varchar/varbinary even for large data
SQL Server 2005 (2) • Multiple Active Result Sets • Simple Enabling • Disabled by default • "MultipleActiveResultSets=True“ in ConnString • Multiple readers on a single connection • Can Open a DataReader while another is open
SQL Server 2005 (2) • Query Notification • SqlDependency • Tracks dependencies on query results • Works in conjunction with the server • Built on top of SQL Server 2005 Query Notifications • Straightforward use • Bind the dependency to the command • Execute the command • Event will be fired if the data changes • Requires SQL Server 2005 and .NET 2.0
SQL Server 2005 (3) • In-Process • Special In-Process Managed Provider • Works with current connection • Allows execution of ResultSets • Similar but *not* the same as SqlClient • Too big to discuss in this talk
ASP.NET 2.0 • DataSources • Bi-directional Databinding • SqlDataSource • Supports RAD methology • Own version of Concurrency Methodology • Relationship to GridView/FormView’s tenuous • Not a ‘best practice’ because the DAL is in the UI • Supports caching • ObjectDataSource • Does not work objects unless specifically created for it • No support for Typed DataSets or ORMs
ASP.NET 2.0 (2) • Data Controls • GridView • Huge improvement on DataGrid • Supports sorting, footers and headers • No good support for a ‘new’ row • FormView • Great control that contains templates for CRUD’ing • EditTemplate, InsertTemplate, ReadOnlyTemplate, etc. • Controls require DataSources • Problematic unless you use the right DAL • DataKeys must be right to work with DataSources
ASP.NET 2.0 • Conclusion • For data access, changes are of limited value • DataSources cause more confusion than clarity • Binding your own objects is harder than it should be • Own type of concurrency is ridiculous • NULL’s in SqlDataSource is just broken • Using 1.1 methodology is hidden in special designer • No upgrade path to evolve projects • Suggestions • Use 1.1 methodology and do it all in code • Use the ASP.NET 2.0 Web Application • http://webproject.scottgu.com/default.aspx
ADO.Next? • Lots of Chatter • LINQ, XLINQ, DLINQ • Entity Data Model • Object Spaces 2.0? • WinFS…DOA
Parting Shots • Doug Tenure…please leave the room! • Data Teams Fractured • ADO.NET -> Data Team • Typed DataSets -> Visual Studio Team • ASP.NET -> ASP.NET Team • Can’t get Data Access that is cohesive • As customers we have to insist they do better…