What's new for DataAdvances in Data Access for Visual Studio 2008

Eric NelsonDeveloper & Platform GroupMicrosoft Ltderic.nelson@microsoft.com http://blogs.msdn.com/ericnel http://twitter.com/ericnel

Not forgetting SQL Server 2008(Actually I am but bare with me...)

RelationalImproved

XMLUDTs

NewFilestreamHierarchy IDDate & TimeSpatial dataSparse columns and wide tablesFiltered indexesChange trackingTable parameters to SP callsResource governorSP control and monitoringDatabase compressionDeclarative management...

SQL Server Integration Services

VSTA replaces VSAADO.NETPerformanceMerge...

Reporting Services“IIS free”TablixNew designer...

BICube designDeisgn alertsPerformance...

.NET 3.5 SP1 gave us...

Data Access over the yearsA

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Accessing data in 2005

ADO.NET, Datasets, DataReaders

Accessing data in 2010

• ORM baby!

Object Relational Mapping

What is it?Technique for working with relational tables as if they were objects in memoryIntention is to hide away the complexity of the underlying tables and give a uniform way of working with data

Why use it?ProductivityRetain database independence

NotesThere are many ORMs for .NET developers already in existence. E.g.

LLBLGen Pro http://www.llblgen.com/Nhibernate http://www.hibernate.org/343.htmlEntitySpaces http://www.entityspaces.net/Portal/Default.aspx

Objects vs Classes vs Entities

Entity Framework

ADO.NET Entity Framework

What is it?Tools and services to create an Entity Data Model

EDM gives ORM to SQL Server, Oracle, DB2 etc

Tools and services for consuming an Entity Data Model

Why use it?ProductivityComplex mapping between entities and database tablesWorks great with ADO.NET Data Services

NotesStrategic but just released...

Entity Data Model

Application modelMapped to a persistence store

Comprised of three layers:

Conceptual (CSDL)Mapping (MSL)Storage (SSDL)

Database agnosticComprised of:

EntitiesAssociationsFunctions

Conceptual

Mapping

Storage

Entity Data Model

{ Creating the EDM }

demo

Entity Data Model Consumption

Entity ClientEntity SQL

Object ServicesEntity SQLLINQ To Entities

Entity Client

Familiar ADO.NET object model:EntityCommandEntityConnectionEntityDataReaderEntityParameterEntityTransaction

Text-based resultsRead-onlyUses Entity SQL

Object Services

Queries materialized as ObjectsObjectContextObjectQuery<T>

Built on top of Entity ClientTwo query options:

Entity SQLLINQ

Runtime services:Unit of workIdentity trackingEager/explicit loading

Entity Framework – Service Stack

LINQ To Entities

Object Services

Entity SQL

Entity Client

ADO.NET Provider

{ Using LINQ to Entities }

demo

EF Providers in Progress

Vendor DB Support

Microsoft SQL ServerOracle Sample, Generic Sample

Devart Oracle, MySQL, Postgress

Phoenix SQLite

IBM DB2, Informix Dynamic Server

MySQL AB MySQL

Npgsql PostgreSQL

OpenLink Many via OpenLink ODBC or JDBC

DataDirect Oracle, Sybase, SQL Server, DB2

Firebird Firebird

LINQ to SQL vs LINQ to Entities 1/2

LINQ to SQL LINQ to Entities

Database Support

SQL Server Many

Object Relational Mapping Capabilities

Simple Complex

Requires Attributed .NET Code

No Yes

Status Released Just Released

Similar – but not quite 2/2

LINQ to SQLvar products = from prod in db.Product where prod.Color == "Blue" select prod;

LINQ to Entitiesvar products = from prod in db.Product where prod.Color == "Blue" select prod;

In general – LINQ to Entities does more – but not always!Only migration that will ever happen is LINQ to SQL migration to LINQ to Entities

Data Services

ADO.NET Data Services

What is it?HTTP access to an object model exposed as RESTful Web ServicesData and/or methodsData returned using ATOM or JSONRead/Write

Why use it?Easy to expose data over the internet accessible by any client

Creating Data Services

Data Access Layer

Entity Framework

Relational

database Other sources

Data Services Runtime

Hosting/HTTP Listener

Custom

Iqueryable/Ienumerable [+ IUpdatable]

HTTP

RESTful Web Services?

Resources

Res 1

Res 2

Res 3

Res 4

HTTP RequestURL

VERB

Payload

HTTP Response

Status

GET

POST

PUT

DELETEXML JSON

Payload

XML JSON

Objects? what kind of objects?

Provide a type with public properties which are;

IQueryable<T>, IEnumerable<T>Also get write access if your type implements;

IUpdatableWorks well with generated code from;

ADO.NET Entity Framework (ObjectContext)LINQ to SQL (DataContext*)

{ Data Services }

demo

Conclusion

•Data Access technology remained reasonably static•Procedural, API access•Surfaced the database schema

1990 to 2007 - Tables

•LINQ – excellent addition to the .NET languages•Entity Framework and the EDM – strategic investment•Data Services – as easy as it gets?•Productivity leap

2008 – Objects

Resourceshttp://blogs.msdn.com/ericnel - all the linksGeneral

ADO.NET Team Blog http://blogs.msdn.com/adonetMike in our team http://www.miketaulty.com ( search Entity or LINQ )Data Platform Developer Centre http://msdn.microsoft.com/en-gb/data/default.aspx

ADO.NET Entity FrameworkEF DM http://blogs.msdn.com/dsimmons FAQ http://blogs.msdn.com/dsimmons/pages/entity-framework-faq.aspx Entity Framework Design http://blogs.msdn.com/efdesign/default.aspx

ADO.NET Data ServicesTeam blog http://blogs.msdn.com/astoriateam

© 2008 Microsoft Ltd. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.

The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the

date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

Appendix

Acronyms

EDM = Entity Data Model

EF = ADO.NET Entity Framework

ESQL = Entity SQL

LINQ = Language Integrated Query

CSDL = Conceptual Schema Definition Language

SSDL = Store Schema Definition Language

MSDL = Mapping Schema Definition Language

Lambda Syntax = customer.Select(...)

Comprehension Syntax = from c in customer ...

SQL = Structured Query Language

Entity Client

Entity Data Model

SSDL

All in one slide SQL

Oracle

Other

CSDL MSL

AD

O.N

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Object Service

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ESQL“select o from

orders”

LINQ to Entities

“from o in orders...”

ADO.NET Data services

Pro

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Pro

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SSDL

SSDL

HTTPCustom

Interceptors

(Query, Update)

Service Operations (Methods)

Entity Data Model

RESTful?

REpresentational State TransferServer-side resources identified by a URIAccess is over HTTP, verb tied to action

GET to read the value of a resourcePOST to create a new resourcePUT to update an existing resourceDELETE to delete a resource

Returned data is “plain” – XML or JSONIs this “the death of SOAP”?