Entity Framework Support
The latest ADO.NET evolution focuses on raising the level of abstraction from the
logical (relational) level to the conceptual (entity) level. For this purpose Microsoft
introduces the Entity Framework, designed to simplify data - object conversion
and embed data access queries into program code.
The Devart dotConnect product line supports the ADO.NET Entity Framework for Oracle,
MySQL, PostgreSQL, SQLite, DB2, and Salesforce.
The article consists of the following sections:
What is ADO.NET Entity Framework?
The Entity Framework is a set of technologies in ADO.NET that support development
of data-oriented software applications. The Entity Framework is designed to enable
developers to create data access applications by programming against a conceptual
application model instead of programming directly against a relational storage schema.
The goal is to decrease the amount of code and maintenance required for data-oriented
applications. Entity Framework applications provide the following benefits:
Applications can work in terms of a more application-centric conceptual model, including
types with inheritance, complex members, and relationships.
Applications are freed from hard-coded dependencies on a particular data engine
or storage schema.
Mappings between the conceptual model and the storage-specific schema can change
without changing the application code.
Developers can work with a consistent application object model that can be mapped
to various storage schemas, possibly implemented in different database management
Multiple conceptual models can be mapped to a single storage schema.
Language-integrated query support provides compile-time syntax validation for queries
against a conceptual model.
Entity Framework Support Key Features
Conceptual approach to enterprise development
Wide support for LINQ to Entities capabilities
Wide support for EntitySQL
Full CRUD (Create, Retrieve, Update, Delete) support
Wide support for server data types
Capability to use stored procedures when manipulating data
Stored procedure import support
Visual Studio EDM Wizard support(reverse engineering of database objects to entity
Visual Studio LightSwitch support
Generate Database Wizard (Model-First) support
Configurable Code-First CreateDatabase/DatabaseExists/DropDatabase functionality
Support for Code-First Migrations with database-specific features
Entity Framework Spatials support
Support for database-specific system functions in LINQ to Entities and Entity SQL
Full-text search support
Entity Framework provider configuration
Using the Entity Data Provider
Use of dotConnect for Oracle in the Entity Framework is similar to use of standard
SqlClient. Generally it conforms to the following scheme:
Open your project.
Add new item ADO.NET Entity Data Model to your project and specify its name.
Choose Generate from database.
Choose the dotConnect you use as data provider and specify the connection string.
Select tables that are actually used in your project and click Generate to finish
the process. If the selected tables contain foreign keys, they will be reflected
in the generated models as well.
Specify a name for the model namespace. Note that this name should be different
from the database (schema) name.
For your convenience there is a brief Entity Framework Tutorial
that you can use to get acquainted with the technology. You can also take a look
at Entity Framework samples available with the product, or download separate
Entity Framework Query Samples package. The latter is a standard Microsoft
demo with added Oracle/MySQL/PostgreSQL/SQLite connectivity.
Deploying an Entity Framework Project
When deploying Entity Framework projects, it is necessary to:
Check if the required assemblies Devart.Data.dll, Devart.Data.Oracle.Entity.EF*.dll,
and Devart.Data.Oracle.dll are available for your application, where * is a number of
Entity Framework version used or "Core" for Entity Framework Core. The assemblies should
reside in GAC or in the application's folder.
If you use Code-First Migrations, you also need to check if the Devart.Data.Oracle.Entity.Migrations.EF*.dll
assembly is available for your application.
For Entity Framework v1 - v6, inform your environment about the provider factory existence (add the entry to the
DbProviderFactories section). This step is not needed for Entity Framework Core. This can be done as follows:
<remove invariant="Devart.Data.Oracle" />
<add name="dotConnect for Oracle" invariant="Devart.Data.Oracle"
description="Devart dotConnect for Oracle"
Version=7.8.301.0, Culture=neutral, PublicKeyToken=09af7300eec23701" />
Replace 7.8.301.0 with your actual version.
If you are registering the provider in the machine.config file, please take into
account the Entity Framework version. Entity Framework v1 - specific applications
require an entry in the .NET Framework 2.0 configuration file, and Entity Framework
v4 - v6 - specific applications should be registered in the .NET Framework
4.0 configuration file. This step is not needed for Entity Framework Core.
You can also read Micrsoft's
Deployment Considerations on ADO.NET Entity Framework.
Visual Model Creation
dotConnects for MySQL, Oracle, PostgreSQL, SQLite, DB2, and Salesforce are tightly
integrated with Visual Studio Entity Data Model Wizard for generating model definitions. dotConnects also include several demo
projects that show how to use the product in conceptual programming against data.
Moreover, dotConnect providers have a bundled visual ORM model designer -
Entity Developer. Entity Developer provides far more advanced model editing
functionality than standard Visual Studio EDM Designer. It provides better support
for Model-First and Database-First development wider mapping support, and powerful
template-based code generation. Visit this
webpage for more information on Entity Developer benefits.
dotConnect providers also support Visual Studio LightSwitch, so you can develop
LightSwitch applications with our providers. You can find a tutorial on creating
a simple LightSwitch application using dotConnect for Oracle here:
Tutorial: How to Connect Visual Studio LightSwitch to Oracle with dotConnect for
Oracle Data Provider.]
Compatibility and Requirements
dotConnects for Oracle, MySQL, PostgreSQL, and SQLite are compatible with the latest
release version of ADO.NET Entity Framework and Visual Studio. The following server versions
are required for Entity Framework to function properly:
Oracle: 18.104.22.168 or higher
MySQL: 5.0 or higher
PostgreSQL: 8.0 or higher
SQLite: any supported version
DB2: 9 and higher