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1 LINQ to “Relational” (L2R) in Visual Studio 2008 SP 1 Mike Taulty Developer & Platform Group Microsoft Ltd [email protected] http://www.miketaulty.com
| Date post: | 10-May-2015 |
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LINQ to “Relational” (L2R) inVisual Studio 2008 SP 1
Mike TaultyDeveloper & Platform GroupMicrosoft [email protected] http://www.miketaulty.com
Where Are We?
“Traditional” ADO.NET Data Access
App CodeApp Code
Customers
ADO.NETADO.NET
DataReaderDataReader
Customers
CommandCommand
““SELECT * SELECT * FROM CUSTOMERS”FROM CUSTOMERS”
DataSetDataSet
“Traditional” ADO.NET Data AccessApp CodeApp Code
Customers
ADO.NETADO.NETLayerLayer
DataReaderDataReader
Customers
CommandCommand
““SELECT * SELECT * FROM CUSTOMERS”FROM CUSTOMERS”
DataDataObjectObject
Load()Load()
CustomerCustomer
FirstNamFirstNameeLastNamLastNamee
......
CustomerCustomer
FirstNamFirstNameeLastNamLastNamee
......
CustomerCustomer
FirstNamFirstNameeLastNamLastNamee
......
CustomerCustomer
FirstNamFirstNameeLastNamLastNamee
......
ORMORM
Language Integrated Queryfrom data in someDataSourcejoin otherData in someOtherSource on keyExpr equals keyExpr (into itemName)?let someVariable = someExpressionwhere somePredicateorderby (expression (ascending | descending)?)*select expressiongroup expression by keyExpression into itemName
.NET Framework V3.5 Service Pack 1.NET Framework V3.5 Service Pack 1
Language Features ( C# V3 and VB V9 )Language Features ( C# V3 and VB V9 )
CustoCustomm
ObjeObjectscts XMLXML SQLSQL EntitiEntiti
eses
6
LINQ is not just relational
Two Different Styles of LINQ from data in someDataSourcejoin otherData in someOtherSource on keyExpr equals keyExpr (into itemName)?let someVariable = someExpressionwhere somePredicateorderby (expression (ascending | descending)?)*select expressiongroup expression by keyExpression into itemName
IEnumerable<TIEnumerable<T>>
IQueryable<T>IQueryable<T>
8
IEnumerable/IQueryable
LINQ is about Query
LINQ specifies a standard syntax for querying dataLINQ has no standard syntax for modifying dataDifferent API’s take a different approach
LINQ to Objects has no approach – unneccessaryLINQ to XMLLINQ to SQLLINQ to Entities
LINQ to Relational ( “L2R” )
LINQ to SQL.NET Framework V3.5SQL Server databases – 2000, 2005, 2008 & CEUses existing ADO.NET SQL Provider
ADO.NET Entity Framework (“LINQ to Entities”).NET Framework V3.5 Service Pack 1Database agnosticNeeds modified ADO.NET Providers
Microsoft ships SQL and example Oracle providerVarious 3rd party providers in progress
L2R – Commonality in Querying
App CodeApp Code
Customers
““LINQ”LINQ”
QueryableQueryableObjectObject
DataReaderDataReader
Customers
LINQLINQQueryQuery
CallCall
ExecuteExecute
ContextContext
GetQueryable<TGetQueryable<T>()>()
Execute<T>()Execute<T>()
CustomeCustomerrFirstNamFirstNam
eeLastNamLastNamee
......
CustomeCustomerrFirstNamFirstNam
eeLastNamLastNamee
......
CustomeCustomerrFirstNamFirstNam
eeLastNamLastNamee
......
Materialise objectsMaterialise objects
ADO.NETADO.NETProviderProvider
Translate to Translate to SQLSQL
ORMMetadata
CreateCreate
L2R – Commonality in Modifying
App CodeApp Code
Customers
““LINQ”LINQ”
ContextContext
CustomeCustomerrFirstNamFirstNam
eeLastNamLastNamee
......
CustomeCustomerrFirstNamFirstNam
eeLastNamLastNamee
......
CustomeCustomerrFirstNamFirstNam
eeLastNamLastNamee
......
““Create”<T>()Create”<T>()
““Delete”<T>Delete”<T>
SaveChanges()SaveChanges()
CreateCreate
DeleteDelete
UpdatUpdatee
StateState
Del Del DelIns Upd
SaveSaveADO.NETADO.NETProviderProvider
Translate to Translate to SQLSQL
ORMMetadata
L2R - Differences
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LINQ to Relational
Resources
© 2008 Microsoft Corporation. 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.
