Starting from version 3.20, Entity Developer provides you with additional features to simplify working with models. Now you can split your model into diagrams to improve its readability. Entity Developer automatically generates a sequence and a trigger for autoincrement fields in Oracle when generating the database script from the model or when synchronizing the database with a model. We constantly work on improving Entity Developer and now we are focusing on performance increase and usability enhancement. The following enhancements have been added in the latest version:

• Large Model Splitting
• Generating Sequences and Triggers for Autoincrement Fields in Oracle

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Go to devart.uservoice.com and share your ideas about Entity Framework support in dotConnect data providers. There you may vote for features that are already in our roadmap, and they will have higher priority in our plans, or you may suggest your own features, and if they will get enough votes, we will include them to the roadmap. Your opinion helps us to make Entity Framework support in dotConnect data providers better and more useful for you.

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April 2011 saw the release of a new version of Entity Framework 4.1; this blog article and samples of code contained in it have been correspondingly updated to match the new features that are now available.

The latest versions of Devart dotConnect for Oracle, dotConnect for MySQL, dotConnect for PostgreSQL, and dotConnect for SQLite contain the most recent version of Code-First (Code Only) support that was added in Entity Framework 4.1. One of the primary advantages of the Code-First approach is a higher level of abstraction from the database and the capability to develop applications using the domain-driven design (DDD) approach.

This article does not provide detailed examples of different aspects related to the use of the Code-First (Code Only) approach. For detailed information on the Code-First approach, see the series of publications on the ADO.NET team blog or MSDN documentation.

This article deals with the following:

• Peculiarities of Dynamic Database Creation and Dropping Implementation
  • Database Creation
  • Database Existence Check
  • Database Dropping
• Code-First Sample
  • Entity Creation
  • DbContext Creation, Mapping Customization
  • Database Fill
  • Database Call
• DefaultConnectionFactory
• Creating Entity Framework Model with Fluent Mapping in Designer
• Code-First for All Databases

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We continue post series about Entity Framework usage. We consider the following questions in this article:

• MS SQL Server and Oracle – how to use both in one EF project?
• DDL is generated with wrong keywords.
• What is the difference between .edml and .edmx models?
• Why setting the StoreGeneratedPattern attribute to "Identity" or “Computed” in Visual Studio 2010 does not work as expected?
  
• How can I avoid loading an entire child collection?

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Some of our users that are working with Entity Framework need to combine Oracle and Microsoft SQL Server in one application. Entity Framework is a powerful ORM with cross-database possibilities, so there is nothing extraordinary in this task.

However, there is a set of pitfalls and difficulties that are not obvious at first glance.

One of our users, Paul Reynolds, has made a series of posts based on his experience for multiple database support in EF:

Preparing for Multiple Databases
Database Caveats
SSDL Adjustments
Database Agnostic LINQ to Entities

In this article we will compare the performance of both most used inheritance types – Table-per-Hierarchy (TPH) and Table-per-Type (TPT), supported by LinqConnect starting from version 2.00. For a better understanding of these inheritance types, we will use the Model First approach when the object model is developed first and after that the database scheme is generated.

To develop an object model, the Entity Developer tool will be used.

Our tests are performed on the following object model:

We have a hierarchy of three entity classes: the base class Gadget and its descendants – MobilePhone and Netbook.
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• Introduction
• Collection with unique elements
• Two and more collections with the repeated elements
• Optimization of the query without obvious collection
• Oracle-specific SQL
• The Afterword

Introduction

Devart was the first company who shipped Entity Framework providers for Oracle, MySQL, PostgreSQL, SQLite. And now we remain the leader in supporting new versions and features of Entity Framework.

Continuing to improve support of Entity Framework v4 features, as it was described here, we have optimized generated SQL for our ADO.NET data providers – dotConnect for Oracle, dotConnect for MySQL, dotConnect for PostgreSQL, and dotConnect for SQLite.

SQL generation was significantly improved and simplified in Entity Framework 4. Most of these improvements can be used in third-party providers, but one aspect has been improved only for SqlClient. It is a conversion of IN expression in Entity SQL and Contains method for collections in LINQ to Entities.

New versions of our dotConnect implement this enhancement for both Entity Framework v4 and Entity Framework v1. Our EF v1 users can get optimized SQL for IN Entity SQL expressions, but LINQ to Entities doesn’t support Contains method for collections in EF v1.
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This article continues series of publications about non-trivial Entity Framework situations encountered by our users.

We consider the following questions in this article:

• Why Oracle raises an exception about too many local sessions
  participating in global transaction when using TransactionScope?
• How can I optimize SQL queries using Entity Framework?
• How can I perform cascade deleting of objects in Entity Framework?
• How can I get the default value of a database field in my Entity Framework project?

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Go to devart.uservoice.com and share your ideas about new features you want to see in LinqConnect. There you may vote for features that are already in our roadmap, and they will have higher priority in our plans, or you may suggest your own features, and if they will get enough votes, we will include them to the roadmap. Your opinion helps us to make LinqConnect better and more useful for you.

We have already started implementing of the following features:

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Nominated products:

• Best Add-In Product – Entity Developer (page 1, category 1: Add-In)
• Best Component Set – dotConnect for Oracle (page1, category 7: Component Set)
• Best IDE Product – dbForge Studio for MySQL (page 2, category 14: IDE)
• Best Free Tool – CodeCompare (page2, category 26: Free Tool )

If some of your favorite products are in this list, please visit: http://www.surveymonkey.com/s/DEVCommChoiceFinalVoting and cast your vote for your favorite Devart products. Voting ends on September 21, 2010.