Devart Blog

How to combine data from several sources using SQL and VirtualQuery

Posted by on July 28th, 2016

The VirtualQuery component allows to perform SQL queries to sources, that are not a database, but a TDataSet or any its descendant. It also allows to connect to several data sources at a time and work with them using SQL queries as with a single data source. Thus, work in heterogeneous environment is implemented, when execution results of queries to different sources can be retrieved in a single data set.

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SQL Server 2016 Stretch Database

Posted by on July 12th, 2016

SQL Server 2016 Stretch Database

On June 1, SQL Server 2016 was released. It brought a large number of novelties into normal development, including the long-announced Stretch Database technology that allows migrating data from SQL Server dynamically to Azure.

From the marketing point of view, Stretch Database has been well promoted. Reasonable arguments were stating that with the growth of historical data the complexity and cost of its maintenance grows as well. As a rational solution to the problem, the automatic migration of obsolescent archival data to the cloud was introduced. Frankly speaking, I enjoyed the idea.

As from SQL Server 2016 RC0, I began testing the Stretch Database technology on two projects I’m helping to develop. The first one is TMetric, a free time tracker with OLTP load, and the second one is an internal project with DW load.
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Getting Real Currency Exchange Rates with Data Generator for SQL Server

Posted by on July 1st, 2016

This article will demonstrate how to get live currency exchange rates with the help of Python and dbForge Data Generator for SQL Server.

Currency exchange rate is the reference information used in the translation of monetary values from one currency to another. The exchange rate expresses the value of one currency in terms of another. Read the rest of this entry »

Devart is the GOLD sponsor of SQLSaturday #508 – Kiev 2016

Posted by on May 24th, 2016

Devart sponsored SQLSaturday #508, that took place on May 21, 2016 in Kiev, Ukraine.

Besides databases, there were a lot of interesting sessions on the popular topics: BI, Data Science, Big Data, Machine Learning, and others.

This year, over 500 attendees have had a great chance to learn something new from world-known speakers from more than 10 countries: Tobiasz Koprowski, Alexander Karl, Mihail Mateev, Dejan Sarka, Uwe Ricken, Michal Sadowski, Satya SK Jayanty, Regis Baccaro, Tomasz Libera, and others. We would like to thank the speakers for the wonderful conference!

SQLSaturday’s are free 1-day training events for SQL Server professionals that focus on local speakers, providing a variety of high-quality technical sessions, and making it all happen through the efforts of volunteers. We would like to express our gratitude to the  organizers — the team that made the event possible.

SQL Saturday #508 – Kiev SQL Saturday #508 – Kiev-1 SQL Saturday #508 – Kiev-2

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Devart attended and sponsored SQL Day 2016 — Annual Conference of Polish SQL Server User Group Association

Posted by on May 24th, 2016

Devart was excited to participate and sponsor SQL Day 2016 that took place on May 16 – 18 in Wrocław, Poland. The event has ended less than a week ago and we are already looking forward to what’s next in 2017!
SQLDay is the largest Microsoft data platform summit in the East Central Europe.

This year, we had a great chance to listen to the biggest stars in global SQL world: Grant Fritchey, Dejan Sarka, Mihail Mateev, Uwe Ricken, Aaron Bertrand, and many others. To see the complete list of speakers, please proceed to the official website. We would like to thank the speakers for the wonderful conference! Read the rest of this entry »

Migrating Entity Framework 6 projects to Entity Framework Core 1 (Entity Framework 7)

Posted by on April 25th, 2016

For the purpose of this tutorial, we will use a test project from the “Entity Framework 6 Support for Oracle, MySQL, PostgreSQL, SQLite, DB2, and Salesforce” blog article. We will update this project so that it could be used with Entity Framework Core 1 (Entity Framework 7).

This is not a full-featured tutorial that completely describes migration of Entity Framework 6 projects to Entity Framework Core (Entity Framework 7). We will describe only several of the possible problems and solutions, which we found when migrating a simple and small project that uses only a small part of Entity Framework 6 features.

As one expects, migration from Entity Framework 6 to Entity Framework Core should have been just the following simple steps:

  • change Target Framework for projects;
  • delete old NuGet package
  • add new NuGet package
  • make some configuration changes (though one can expect some vertical compatibility between different versions of the same ORM, and consider this step unnecessary).

That should have been all the steps. However, in reality there are much more problems than one should expect. And in this article we will describe some of these problems and their solutions.

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Entity Framework Core 1 (Entity Framework 7) Support

Posted by on April 25th, 2016

Entity Framework Core 1, formerly known as Entity Framework 7 (hereafter also called EF Core or EF7), is supported in Devart ADO.NET provider product line. It is supported in providers for relational databases: Oracle, MySQL, PostgreSQL, SQLite, DB2, and provides for cloud data sources, such as Salesforce, Dynamics CRM, SugarCRM, Zoho CRM, QuickBooks, FreshBooks, MailChimp, ExactTarget, Bigcommerce, Magento. Currently our providers support Entity Framework Core Release Candidate 1. Entity Framework Core support is currently in public beta stage. It is implemented for the full .NET Framework platform – .NET Framework 4.5.1 and higher.

We need to mention first that Entity Framework Core 1 (Entity Framework 7) – is a completely new ORM, which inherited only the name, LINQ support, and some classes with the same or similar names from Entity Framework 6, and even these classes often have incomplete functionality in comparison to their Entity Framework 6 counterparts. You can find more information about EF Core compatibility with EF6 and issues of migration in other our article, “Migrating Entity Framework 6 projects to Entity Framework Core 1 (Entity Framework 7)”. Additionally you can study Entity Framework Core features in its official documentation.

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Devart Took Part in the Kharkiv International Marathon

Posted by on April 14th, 2016

Devart team took part in the 3rd Annual Kharkiv International Marathon, that took place on April 9, in city of Kharkiv, Ukraine.

Gorgeous sunny weather, wonderful organization and cheerful atmosphere helped our runners to get through both, 4.2K ad 10K runs and finish with pretty good results.

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SQL Server Execution Plans

Posted by on April 12th, 2016

One of the best methods to analyze the query performance is to explore the query execution plan. A query plan or query execution plan is an ordered set of steps utilized to access data in a SQL relational database management system. In this article, we will discuss the basics of the Query Execution Plan feature available in SQL Server. Read the rest of this entry »

Generating Related Data Elements with dbForge Data Generator for SQL Server

Posted by on April 1st, 2016

Recently we got an interesting question from our user:

The docs don’t address directly, but how can we generate three related data elements, like date of birth, age, and date of death for instance, in one script efficiently as it generates test rows/records and then populate the fields in a test database table? If docs do address this, please point me to where, if you would… Thanks!

Another user has posted the similar question on the Devart support forum. Read the rest of this entry »