SQL commands

Aveek Das
Binary Search Tree Example

Diving deep with complex Data Structures

July 29, 2020 by

In my previous article, Understanding common Data Structures, I have mentioned the most commonly used data structures in software programming. In this article, let us get into some more details about the other data structures that are a bit complex than the ones already discussed but also used quite often while designing software applications. Here, we will look into the following data structures.

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Emil Drkusic
Naming convention - the data model

Learn SQL: Naming Conventions

July 28, 2020 by

A naming convention is a set of unwritten rules you should use if you want to increase the readability of the whole data model. Today, I’ll try to explain how you should formulate your naming convention and, maybe even more important, why should you do it and what is the overall benefit from using it.

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Aveek Das

Understanding the SQL MERGE statement

July 27, 2020 by

In this article, I am going to give a detailed explanation of how to use the SQL MERGE statement in SQL Server. The MERGE statement in SQL is a very popular clause that can handle inserts, updates, and deletes all in a single transaction without having to write separate logic for each of these. You can specify conditions on which you expect the MERGE statement to insert, update, or delete, etc.

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Aveek Das

Understanding common Data Structures

July 15, 2020 by

In this article, I am going to walk you through the concepts of the common Data Structures that every student, colleague working with computers should be aware of. Data Structure forms an integral part of any system or database design. It is a very interesting and intuitive concept that you can apply anywhere. Through this article, I aim to introduce the beginners to the concepts of Data Structures and brush up the same for colleagues who have already been associated with the industry for years. This will also help you understand some database concepts more easily once you have a grasp over these concepts.

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Bojan Petrovic
Results grid showing before and after values of the Vacation Hours column

SQL UPDATE syntax explained

July 10, 2020 by

This article will get you familiar with the SQL UPDATE syntax and demonstrate how this statement can be used for modifying data using T-SQL. Data modification side of DML language in T-SQL includes three statements used for modifying data in SQL Server and those are: INSERT, UPDATE, and DELETE. The focus here will be on the UPDATE statement explicitly.

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Frank Solomon

Lever T-SQL for Pinpoint Control of ORDER BY in a Stored Procedure

June 1, 2020 by

Introduction

The T-SQL ORDER BY clause sorts SQL Server SELECT statement result sets, and it becomes important when we build stored procedures. Unfortunately, the syntax offers no flexible way to directly control the ORDER BY clause behavior with argument values. This means we don’t have an easy way to control the specific column or columns that the ORDER BY clause sorts. Additionally, SQL Server does not offer a flexible way to directly control the ascending or descending order of any ORDER BY clause column with argument values. Of course, we can certainly hard-code the ORDER BY clause in a stored procedure, but this approach becomes fixed in stone. We could try a dynamic SQL solution, involving a stored procedure code that dynamically builds and executes SQL Server statements inside a stored procedure. However, this technique becomes tricky, and it can lead to SQL injection attacks. Other techniques might rely on CASE statements, and their complexity can become overwhelming as the column count grows. This article spotlights a clean, efficient, pinpoint T-SQL stored procedure technique that directly sorts one, some, or all SELECT statement result set columns. The technique avoids dynamic SQL, and it operates directly in a stored procedure. The article also shows how to set the ascending or descending sort order of specific columns.

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Emil Drkusic
SQL Server PIVOT TABLE - the data model we'll use

Learn SQL: SQL Server Pivot Tables

May 11, 2020 by

In the previous few articles in this series, we’ve set the foundations on how to create a report. We’ll take one step further and see how to use the SQL Server PIVOT table operator. We’ll start from the simple query and slowly progress towards dynamic SQL and PIVOT. Let’s start.

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Frank Solomon
Run the DYNAMIC_ROW_NUMBER_PARTITIONS stored procedure with a T-SQL EXEC statement, and see the result set.

Lever T-SQL to dynamically define duplicate SQL Server database table rows

May 11, 2020 by

Introduction

Lever T-SQL to handle duplicate rows in SQL Server database tables article highlighted T-SQL features that detect and handle duplicate SQL Server table rows. The techniques work well, but they rely on fixed duplicate row definitions. This article extends those techniques, showing how to define duplicate rows in a dynamic way.

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Emil Drkusic
SQL Server date and time functions - the data model we'll use in the article

Learn SQL: SQL Server date and time functions

April 21, 2020 by

So far, we haven’t talked about SQL Server date and time functions. Today we’ll change that. We’ll take a close look at the ones most frequently used and mention all other date and time functions as well. This will be also the first step to create reports, including date and time functions. We’ll do that in upcoming articles in this series.

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Esat Erkec
What is pagination in SQL Server?

Pagination in SQL Server

April 14, 2020 by

Pagination is a process that is used to divide a large data into smaller discrete pages, and this process is also known as paging. Pagination is commonly used by web applications and can be seen on Google. When we search for something on Google, it shows the results on the separated page; this is the main idea of the pagination.

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Emil Drkusic
SQL Examples - the data model we'll use in the article

Learn SQL: SQL Query examples

March 31, 2020 by

In the previous article we’ve practiced SQL, and today, we’ll continue with a few more SQL examples. The goal of this article is to start with a fairly simple query and move towards more complex queries. We’ll examine queries you could need at the job interview, but also some you would need in real-life situations. So, buckle up, we’re taking off!

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