dotConnect

Spatials Overview

Entity Framework v5 introduces spatial data types support. They are represented as two new DbGeometry and DbGeography data types from System.Data.Entity.dll in .NET Framework 4.5.

Many our Oracle users use Oracle Spatial functionality in their projects. Before Entity Framework v5 there was no easy way to use Oracle Spatial with Entity Framework, though users of PostgreSQL, PostGIS, and SharpMap could use this cumbersome and limited workaround. This workaround was even harder to use with Oracle Spatial and was almost not used because of numerous limitations.

Now Entity Framework v5 changes the situation, and Devart dotConnect for Oracle provides the best possible support for Entity Framework Spatials and Oracle Spatial. It includes new versions of Devart.Data.Oracle.Entity.dll and Devart.Data.Oracle.Entity.Migrations.dll assemblies built for .NET Framework 4.5 (Entity Framework v5) and the new unsigned Devart.Data.Oracle.Entity.SharpMap.dll assembly for SharpMap library support.
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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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• 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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In this article we continue series of publications about non-trivial situations encountered by our users. Some of these situations are the restrictions of the used platforms, and some simply require a nonstandard approach to solving the problem.

We consider the following questions in this article:

• How can I execute native SQL using Entity Framework?
• How can I use Self-Tracking Entities (STE) or POCO in the Devart Entity Model?
• How can I use Oracle stored procedures with a boolean parameter in Entity Framework?
• How to work with UNION in Entity Framework

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This article will open a series of publications about non-trivial situations encountered by our users. Some of these situations are the restrictions of the used platforms, and some simply require a nonstandard approach to solving the problem.

Our first post consists of the following users’ questions concerning Entity Framework:

• How to provide the current datetime for record filtering?
• How can I use XML-types from Oracle tables in the Entity Framework model?
• Is ORA_ROWSCN type useful for concurrency handling in Entity Framework?
• What is "outer apply" statement and why isn’t it supported in the Entity Framework statements?

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