LINQ to SQL and ADO.NET Entity Framework
are extensions of ADO.NET and are introduced to avoid difficulties involved in
writing programs using object oriented programming languages to access data
residing in RDBMS.
LINQ To SQL
|
Entity Framework
|
|
Complexity
|
LINQ
To SQL is easier to use.
|
Entity
Framework is more complex compared to LINQ To SQL.
|
DB
Server Support
|
LINQ
To SQL supports only Microsoft SQL Server.
|
Entity
Framework is built on top of ADO.NET data provider model and thus supports
all existing ADO.NET data providers i.e. IBM DB2, Sybase, Oracle, SQL Azure etc.
|
File
Type
|
It
uses Database Markup Language (DBML) file that contains XML mappings of
entities to tables.
|
Entity
Framework uses four files EDMX, CSDL, SSDL and MSL. The later three are
generated at runtime.
|
Purpose
|
Used
for rapid application development.
|
EF
is used for enterprise n-tier application.
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Coupling
|
LINQ
To SQL is tightly coupled - object property to specific field of database or
more correctly object mapping to a specific database schema
|
EF
is loosely coupled.
|
Model
|
LINQ
To SQL provides one-to-one mapping of tables to classes.
|
Entity
Framework enable decoupling DB Server (Database Schema) and Entity Representation
in terms of Model (Conceptual Schema). You can map one table to multiple
entities or multiple tables to one entity.
|
Mapping
Type
|
In
LINQ To SQL each table is mapped to single class. Join table must be
represented as a class. Also, complex types cannot be easily represented
without creating separate table.
|
In
Entity Framework a class can map to multiple tables.
|
Inheritance
|
In
LINQ To SQL inheritance is difficult to apply. It supports Table Per Class Hierarchy
(TPH).
|
In
Entity Framework inheritance is simple to apply. It supports Table Per Class Hierarchy
(TPH) and Table Per Type (TPT). It also provides limited support of Table Per
Concrete Class (TPC).
|
Complex
Type
|
LINQ
To SQL does not support the creation of complex types.
|
Entity
Framework supports the creation of complex types.
|
Complexity
|
LINQ
To SQL is simple to learn and implement for Rapid Application Development,
but it will not work in complex applications.
|
Entity
Framework has more features which will take time to learn and implement, but
it will work in complex applications.
|
Query
Capability
|
LINQ
To SQL has DataContext object through which we can query the database.
|
With
the Entity Framework, we can query database using LINQ To Entities through
the ObjectContext object and ESQL (provides SQL like query language). In
addition, Entity Framework has ObjectQuery class (used with Object Services
for dynamically constructing queries at runtime) and EntityClient provider (runs
query against conceptual model).
|
Performance
|
LINQ
To SQL is slow for the first time run. After first run provides acceptable
performance.
|
Entity
Framework is also slow for the first run, but after first run provides
slightly better performance compared to LINQ To SQL.
|
Generate
Database from Model
|
It
has no capability to generate database from Model.
|
Entity
Framework supports generation of database from Model.
|
Future
Enhancement
|
Microsoft
intended to obsolete LINQ To SQL after the Entity Framework releases. So it
will not receive any future enhancements.
|
Entity
Framework has future enhancements.
|
So while there is a lot of overlap, LINQ to SQL is targeted
more toward rapidly developing applications against your existing Microsoft SQL
Server schema, while the Entity Framework provides object- and storage-layer
access to Microsoft SQL Server and 3rd party databases through a loosely
coupled, flexible mapping to existing relational schema.
For detailed description about EF with sample please check here
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