T-SQL

Emil Drkusic
SQL-related jobs - the data model

Learn SQL: SQL-Related Jobs

September 1, 2020 by

In today’s article, we’ll take a look at 4 common SQL-related jobs and roles and explain what kind of tasks you could expect at each of these roles and what types of queries you’ll possibly use to solve these tasks. If you’re already in any of these roles, you’re probably familiar with this, but if you’re new to the world of SQL, you could find this very useful to decide in which way you want your career to develop.

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Rajendra Gupta
Copy file using the xp_cmdhell

T-SQL scripts to copy or remove files from a directory in SQL Server 2019

August 21, 2020 by

Sometimes database professionals need to perform specific tasks at the operating system level. These tasks can be like copying, moving, deleting files and folders. A use case of these tasks might be removing the old backup files or copying backup files to a specific directory after a particular time. In SQL Server, we can use xp_cmdshell extended stored procedure to execute commands directly in the Windows command prompt(CMD). You need a sysadmin role or proxy account configured to use this extended procedure. We can also use the SSIS package for the file transfer, but it also requires you to build a package with the relevant tasks.

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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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Jignesh Raiyani
Calling SQL Server Procedure inside the Function

Execute a SQL Server procedure inside a function

June 23, 2020 by

In this article, we will ensure that the execution of the SQL Server procedure inside the function is possible. A common understanding of the database developer is that the procedure cannot be utilized or executed inside a user-defined function because the user-defined function does not allow performing DML operation with the table. The procedure is allowed to play with the database and its property, whether a user-defined function isn’t. That should be the essential reason behind allowing the execution of a SQL Server procedure inside the function.

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Dinesh Asanka
SQL Service Broker objects in the SQL Server Management Studio after creating them.

Using the SQL Server Service Broker for Asynchronous Processing

June 10, 2020 by

Introduction

In the real-world implementation of SQL Server of an enterprise system, it always needs to implement data in multiple databases. In most of the cases, a single transaction will span across multiple databases. If there are multiple databases, there will be performance issues and implementation issues during the cross-database transactions. However, with the use of SQL Service Broker that was introduced in SQL Server 2005, you can implement asynchronous transactions between databases.

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Timothy Smith
We can see the option to enforce password policy when we manually create a login through the interface or selecting this option as ON when scripting logins for creation

Security Testing SQL Logins with the PWDCOMPARE function

June 3, 2020 by

In this article, we’ll look at using the built-in PWDCOMPARE function in SQL Server for security testing passwords. While this tool may seem like it exposes a weakness in Microsoft SQL Server because we can test for passwords, it should be of note that an attacker could do the same attack by attempting to login to our database server assuming the attacker was able to access a connection to it. Therefore, this function does not increase the risk of an attack on SQL Server but does help us identify possible weaknesses in our environment so that we can quickly mitigate these risks. In addition, we’ll also combine this with other related tools in SQL Server to help us with logins.

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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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