CHECK Constraints in SQL Server

In this article, we will talk about CHECK constraints. We will see how to add CHECK constraints to SQL Server table columns and discuss the pitfalls you may encounter when using this type of SQL Server constraints.

CHECK constraint basics

CHECK constraints are simply conditional statements (predicates that return TRUE or FALSE) that refer to table columns for maintaining data integrity. When one inserts data into a column or several columns in a single row, CHECK constraints come into action. They evaluate the data to be inserted. In case the data does not meet the condition specified in the CHECK constraint, the insertion fails.

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Creating and Accessing In-Memory OLTP Databases and Tables

This is the second article in a series of articles about SQL Server In-Memory OLTP.

The introductory article — SQL Server In-Memory OLTP, briefly introduced the basics of the new Hekaton engine. In this part, we will focus on practice. To be more specific, we will see how to create In-Memory optimized databases and tables, and also, how to assess them with help of T-SQL. (more…)

Pivot Tables in MySQL

  1. Briefly about Pivot tables
  2. Pivoting data by means of tools (dbForge Studio for MySQL)
  3. Pivoting data by means of SQL
  4. Automating data pivoting, creating query dynamically

Briefly about Pivot tables

This article deals with the transformation of table data from rows to columns. Such transformation is called pivoting tables. Often, the result of the pivot is a summary table in which statistical data are presented in the form suitable or required for a report. (more…)

Handling a GDI Resource Leak

GDI leak (or, simply the usage of too many GDI objects) is one of the most common problems. It eventually causes rendering problems, errors, and/or performance problems. The article describes how we debug this problem.

In 2016, when most programs are executed in sandboxes wherefrom even the most incompetent developer cannot harm the system, I am amazed to face the problem I will speak about in this article. Frankly speaking, I hoped that this problem had gone forever together with Win32Api. Nevertheless, I faced it. Before that, I just heard horror stories about it from old more experienced developers. (more…)

ASP.NET Core 1.0. Platform. Part 2. ASP.NET Today or what to choose?

Many of us (including myself) have been waiting for the final version of .NET Core and ASP.NET Core. Now the wait is over – a couple of months ago the RTM version of the web app development technology named ASP.NET Core 1.0, has been released. Just a reminder: in early 2016 it was branded as ASP.NET 5. All new features of the new version of the Microsoft.NET platform have been described in general terms. In this article and subsequent articles, you will learn what else can be done with the latest .Net platform. I will also provide a broad description of the web development technologies that Microsoft offers today. To see what is available at the moment, we can just open Visual Studio 2015 Update 3 with the latest version of ASP.NET and Web Tools (VS2015Tools.Preview2.0.1).

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ASP.NET Core 1.0. Part 1: Introduction, general description and the future of .NET Framework

The question is: “Microsoft ASP.NET vNext: evolution or revolution?“, the absolute answer is revolution. In this series of articles, I will try to describe in detail the latest technology for creating web applications, namely – ASP.NET vNext, which initially had the official name ASP.NET 5 and later was renamed to ASP.NET Core 1.0. There will be another series devoted to the development of a real application with examples describing the practical use of this technology.

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Azure SSAS. Cubes in Clouds

Autumn of 2016 was full of events from Microsoft dedicated to analytics. In practice, the company began aggressive promotion of its predictive analytics and BI platform in the cloud. Finally, it has happened – Microsoft has released the preview of Azure SSAS Tabular. In fact, the company has transferred SSAS Tabular to the cloud. Therefore, SQL Server Analysis Enterprise Edition in cloud  supports DirectQuery, partitions, row-level security, bi-directional relationships, and has compatibility level 1200.

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SQL Server Security Ponderings – Part 1 | DMI – Bobby Returns

Nowadays security and data privacy are in special focus. When I deliver a training, I always refer to a DBA as the “guardian of the data.” There are two aspects of being a guardian.

The first one is integrity. It includes tasks like checking database consistency, creating backups and in case of problems being prepared to fix the database by having well designed, comprehensive DR plan.

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SQL Server In-Memory OLTP

This is the first article in a series of articles about In-Memory OLTP. It helps you to understand how the new Hekaton engine works internally. We will focus on details of in-memory optimized tables and indexes. This is the entry-level article, which means you do not need to be an SQL Server expert, however, you do need to have some basic knowledge about the traditional SQL Server engine. (more…)