LINQ versus Entity Framework

Question

I am at the crossroads here on whether to stick to using LINQ to perform data access operations or use Entity Framework. I have spent greater part of this year Learning LINQ and need to know whether I should stick to this or jump into Entity Framework model. I hear it is a more robust architecture but need advise on what to do.

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akoranteng

Answer 1

Greeting,

If your database is straightforward and simple, LINQ to SQL will do. If you need logical/abstracted entities on top of your tables, then go for Entity Framework.

Entity Framework than LINQ to SQL because many reasons as follows.

• It is more flexible to mapping entity model to database. You can map one class to multiple tables, using inheritance.
• It supports many queries, you can use LINQ to Entities, Entity SQL, Object Services and Entity Client.
• When the database schema is changed, you can synchronize entity model from latest database.
• It has better overall performance when compare with LINQ to SQL.
•  It will be improved many features in the VS2010. You will create complex data type, generate database from entity model.
• It supports many database vender other than SQL Server.

Additional Information :

Note 1: LINQ to Entities (ADO.Net Entity Framework)

LINQ to Entities (ADO.Net Entity Framework) is an ORM (Object Relational Mapper) API which allows for a broad definition of object domain models and their relationships to many different ADO.Net data providers. As such, you can mix and match a number of different database vendors, application servers or protocols to design an aggregated mash-up of objects which are constructed from a variety of tables, sources, services, etc.

Entity Framework is the all-out, no-holds-barred way to do it. This means you will take more time up-front, develop slower, and have more flexibility if you are working on something larger.Entity Framework supports variety databases (DB2, MySql, Sybase and more) .

If you are writing an application that requires any of the following features, you should use the ADO.NET Entity Framework:

• The ability to define more flexible mapping to existing relational schema, for example:
• Mapping a single class to multiple tables
• Mapping to different types of inheritance
• Directly Modeling Many to Many relationships
• Mapping to an arbitrary query against the store
• The ability to query relational stores other than the Microsoft SQL Server family of products.
• The ability to share a model across Replication, Reporting Services, BI, Integration Services, etc.
• A full textual query language
• The ability to query a conceptual model without materializing results as objects.

Note2 : LINQ to SQL



LINQ to SQL is the quick-and-easy way to do it. This means you will get going quicker, and deliver quicker if you are working on something smaller.LINQ to SQL only supports 1 to 1 mapping of database tables, views, sprocs and functions available in Microsoft SQL Server. It's a great API to use for quick data access construction to relatively well designed SQL Server databases. LINQ2SQL was first released with C# 3.0 and .Net Framework 3.5.LINQ to SQL  is tightly coupled - object property to specific field of database or more correctly object mapping to a specific database schemaLinq to sql is best matching for domain model with specific sql server scheme.


The following table provides a summary of the feature set  comparison between the two LINQ to SQL and Linq to Entities.

Feature	LINQ to SQL	LINQ to Entities
Language Extensions Support	Y	Y
Language Integrated Database Queries	Y	Y
Many-to-Many (3way Join/Payload relationship)	N	N
Many-to-Many (No payload)	N	Y
Stored Procedures	Y	N (to be added)
Entity Inheritance	N	Y
Single Entity From Multiple Tables	N	Y
Identity Management / CRUD features	Y	Y

Hope this helps you out.

Take Care

PL

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Helping People To Solve Technical Problems

Answer 2

Greetings

The table shows the difference between LINQ and Entity Framework.

Compare features for LINQ to SQL vs Entity Framework

Feature	LINQ to SQL	Entity Framework
Model	domain model	conceptual data model
Databases Supported	SQL server only	variety of databases
Data Sources	tables only	tables, replication, reporting Services, BI and etc
Complexity	simple to use	complex to use
Development Time	rapid development	slower development but more capabilities
Mapping	class to single table	class to multiple tables
Inheritance	hard to apply	simple to apply
File Types	dbml file only	after compilation generate edmx file with 3 sections to represent the schema: csdl, msl and ssdl
Create complex properties (e.g. Customer type may have Address property that is an Address type with Street, City, Region, Country and Postal code properties)	Not Support	Support in VS2010 Beta 1 but we can manually modify in .edmx file.
Query	1. LINQ to SQL (for select) 2. Data Context (for update, create, delete, store procedure, view)	1. LINQ to Entities (for select)2. Entity SQL (is a derivative of Transact-SQL, it supports inheritance and associations)  3. Object Services (for update, create, delete, store procedure, view) 4. Entity Client (is an ADO.NET managed provider, it is similar to SQLClient, OracleClient, etc. It provides several components like EntityCommand, EntityTransaction)
Can synchronize with Database if Database Schema is changed	Not Support	Support
Performance	Very slow for the first query	Very slow for the first query. But overall performance is better than LINQ to SQL (Please see the result in the attach file)
Continue to improve features in the future	No	Yes
Generate database from entity model	Not Support	It will support in VS2010 Beta1.

Hope this helps you out.

Take Care

PL

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Helping People To Solve Technical Problems

Answer 3

Thanks a whole lot for the information. Could you poiunt me to any good links/samples to get me started. I am using Julie Lerman's book but it looks slightly advanced for a beginner.

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akoranteng

Answer 4

Greetings

Code Samples :

ADO.NET Entity Framework Tutorial with LINQ to Entities, method expressions, and stored procedures
http://www.codeguru.com/csharp/csharp/cs_linq/article.php/c15489/

ADO.NET Entity Framework Query Samples
http://code.msdn.microsoft.com/EFQuerySamples

Entity Framework Documentation Samples for Visual Studio 2008
http://code.msdn.microsoft.com/EFDocSamples2008


EDM Metadata Samples
http://code.msdn.microsoft.com/EdmMetadataSamples

     
Getting started with ADO.NET Entity Framework in .NET 3.5
http://www.c-sharpcorner.com/UploadFile/ankithakur/Getting_started_with_ADO_NET_Entity_Framework09302008085544AM/Getting_star
ted_with_ADO_NET_Entity_Framework.aspx


ADO.NET Entity Framework as Data Access Layer
http://www.codeproject.com/KB/database/ADO_NET_Entity_Framework.aspx

Modeling Enterprise Applications with Entity Framework
http://www.codeproject.com/KB/architecture/LinqEntityFramework.aspx

DDD and the ADO.NET Entity Framework
http://www.codeproject.com/KB/architecture/ddd_and_entityframework.aspx


Introduction to the Entity Framework
http://www.codeproject.com/KB/database/IntroEntityFramework3.aspx

Business Logic with Entity Framework
http://www.codeproject.com/KB/database/EntityFrameworkLogic.aspx

Simple Sample with Entity Framework
http://www.codeproject.com/KB/database/sample_entity_framework.aspx

Free your model from view-imposed restraints with Entity Framework Interceptors
http://www.codeproject.com/KB/linq/entity_interceptors.aspx


Query Expression Syntax Examples (LINQ to Entities)
http://msdn.microsoft.com/en-us/library/bb738646.aspx

AdventureWorks Sales Model (EDM)

The Adventure Works Sales Model contains entities and associations that are used by example code in other topics in the
Entity Data Model (EDM) documentation. This Sales model uses the AdventureWorks database sample. For more information about how to generate the AdventureWorks Sales Model, see How to: Manually Define an Entity Data Model (Entity Framework).

http://msdn.microsoft.com/en-us/library/bb387147.aspx

Method-Based Query Syntax Examples (LINQ to Entities)

This section provides LINQ to Entities programming examples in method-based query syntax that use the standard query
operators. The AdventureWorks Sales Model used in these examples is built from the Contact, Address, Product,
SalesOrderHeader, and SalesOrderDetail tables in the AdventureWorks sample database.

http://msdn.microsoft.com/en-us/library/bb896265.aspx






Sample Links are given below for ADO.NET Entity Framework

ADO.NET Entity Framework - Very Important Link , Go through it.
http://msdn.microsoft.com/en-us/library/bb399572.aspx

ADO.NET Entity Framework Overview
http://msdn.microsoft.com/en-us/magazine/cc163399.aspx

Getting Started (Entity Framework)
http://msdn.microsoft.com/en-us/library/bb386876.aspx

Generating an Entity Data Model
http://msdn.microsoft.com/en-us/library/bb399596.aspx

Mapping a Conceptual Model to a Storage Schema
http://msdn.microsoft.com/en-us/library/bb399232.aspx

Working with Entity Data
http://msdn.microsoft.com/en-us/library/bb399760.aspx

Quickstart (Entity Framework)
http://msdn.microsoft.com/en-us/library/bb399182.aspx

Entity Framework Resources
http://msdn.microsoft.com/en-us/library/bb738448.aspx

Entity Framework Terminology
http://msdn.microsoft.com/en-us/library/bb387161.aspx

Application Scenarios (Entity Framework)
http://msdn.microsoft.com/en-us/library/bb738689.aspx

Feature Reference (Entity Framework)
http://msdn.microsoft.com/en-us/library/bb738623.aspx

Querying with LINQ to Entities
http://msdn.microsoft.com/en-us/library/bb738458.aspx

Entity Data Model Tools
http://msdn.microsoft.com/en-us/library/bb399249.aspx

ADO.NET Entity Data Model Designer Scenarios
http://msdn.microsoft.com/en-us/library/cc716693.aspx

Entity Data Model Wizard
http://msdn.microsoft.com/en-us/library/bb399247.aspx

ADO.NET Entity Data Model Designer
http://msdn.microsoft.com/en-us/library/cc716685.aspx

Schemas and Mapping Specification (Entity Framework)

Using the Entity Data Model (EDM) to build applications based on the Entity Framework requires writing three XML
specifications.The first specification uses conceptual schema definition language (CSDL) to declare and define the entities, associations, sets, and containers of the object model being designed. The programmable classes are built from this schema.The second specification in store schema definition language (SSDL) describes the data source that persists data for applications built on the EDM.The third specification written in mapping specification language (MSL) maps the declarations in the CSDL file to the data source described in the SSDL file.These schemas and the mapping specification that connects them are written in XML. The topics in this section provide the details of CSDL, SSDL, and MSL, and include examples demonstrating how the sets and containers in each file are connected to implement a programmable object model.

http://msdn.microsoft.com/en-us/library/bb399604.aspx

Entity SQL Overview

Entity SQL Overview - VERY IMPORTANT LINK REGARDING ENTITY SQL LANGUAGE - GO THROUGH IT.
http://msdn.microsoft.com/en-us/library/bb387145.aspx

Entity SQL Reference
http://msdn.microsoft.com/en-us/library/bb387118.aspx

Entity SQL Language
http://msdn.microsoft.com/en-us/library/bb399560.aspx

How Entity SQL Differs from Transact-SQL
http://msdn.microsoft.com/en-us/library/bb738573.aspx

Entity SQL Quick Reference
http://msdn.microsoft.com/en-us/library/bb738683.aspx

Type System (Entity SQL)
http://msdn.microsoft.com/en-us/library/bb399353.aspx

Hope this helps you.

Take Care

PL

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Helping People To Solve Technical Problems

Answer 5

The table "Compare features for LINQ to SQL vs Entity Framework" appears to have been included here without attribution (Oct 31, 2009 2:33 AM post) .

It appears to be copied from...

http://www.osellus.com/blogs/2009/06/04/linq-to-sql-vs-entity-framework/