SQL commands

SQL Cheat Sheet for Newbies

February 21, 2023 by Esat Erkec

In this SQL cheat sheet, we’ll look at sample SQL queries that can help you learn basic T-SQL queries as quickly as possible.

How to use the CROSSTAB function in PostgreSQL

February 17, 2023 by Rajendra Gupta

This article will explore the use of the CROSSTAB function in PostgreSQL.

Learn the PostgreSQL COALESCE command

January 19, 2023 by Rajendra Gupta

This article will make you learn the Postgres Coalesce command with examples.

Learn SQL standard deviation function

January 17, 2023 by Hadi Fadlallah

This article will show the SQL standard deviation function with several examples.

An overview of the SQL GROUP BY clause

December 28, 2022 by Hadi Fadlallah

This article briefly explains the SQL group by clause, when it should be used, and what we should consider when using it.

Use of the RESTORE FILELISTONLY command in SQL Server

December 21, 2022 by Rajendra Gupta

This article explores the RESTORE FILELISTONLY command in SQL Server with examples.

Introduction

Performing a database backup is an integral part of a DBA’s job. Backups are taken to ensure that data can be recovered in an emergency. There are different restore mechanisms, and the SQL Server DBA needs to understand them to make the right decision in each situation.

The difference between WHERE and HAVING clause in SQL

December 16, 2022 by Randheer Parmar

This article aims to explain the WHERE, GROUP By, and HAVING clauses in detail. Also, we will see the difference between WHERE and HAVING with examples.

How to add or subtract dates in SQL Server

December 15, 2022 by Rajendra Gupta

This article explores SQL Server functions to add or subtract dates in SQL Server.

Why do we need Correlated Subqueries in SQL

December 9, 2022 by Haroon Ashraf

This article speaks about correlated subquery and why we need it when querying a SQL database.

Additionally, we are going to understand the difference between simple subqueries and correlated subqueries with the help of some easily understandable examples.

Different SQL TimeStamp functions in SQL Server

November 25, 2022 by Rajendra Gupta

This article will show different SQL timestamp functions available with examples.

xp_cmdshell and sp_xp_cmdshell_proxy_account stored procedures in SQL Server

June 22, 2022 by Hadi Fadlallah

This article explains the xp_cmdshell and sp_xp_cmdshell_proxy_account system stored procedures in SQL Server and how developers can use them to execute Windows commands.

Lever the TSQL MAX/MIN/IIF functions for Pinpoint Row Pivots

May 16, 2022 by Frank Solomon

Introduction

For a recent Tsql development project involving text document records, the customer wanted a product that would show the latest and most recent earlier version of specific document text stored in a SQL Server 2014 database. One result set row had to hold all relevant information for each document: both document versions as described above, and relevant metadata. This essentially required fine-grained row pivots. This article will describe the engineering behind the solution, and compare that solution with the SQL Server PIVOT operator.

An overview of DIFFERENCE and SOUNDEX SQL functions

January 18, 2022 by Hadi Fadlallah

This article gives an overview of DIFFERENCE and SOUNDEX SQL Server built-in system functions. It explains how to use those functions and how do they work.

Getting started with SQL Server CLR functions

January 11, 2022 by Hadi Fadlallah

This article will explain how to create a SQL Server CLR function stored in a C# class library without creating a SQL Server database project. We will first briefly explain the concept of .NET common language runtime (CLR) and then build a C# class library using the .NET framework. Then, we will use the C# library to create user-defined CLR functions in SQL Server.

Understanding the SQL MIN statement and its use cases

December 3, 2021 by Manvendra Singh

Today, I will explain an overview of the SQL MIN () function along with its several use cases in this article. This function is categorized under aggregate functions in SQL Server. Aggregate functions perform a calculation on a set of values from a specified expression and return a single value in their output. Aggregate functions return the same value every time you execute them unless your source data is changed.

SQL commands in SQL Server

November 22, 2021 by Daniel Calbimonte

Introduction

If you are here, it means that you want to learn the SQL commands. This article applies to SQL Server especially, but most of the theory is similar to Oracle, MySQL, MariaDB, PostgreSQL, and other databases. The SQL commands are instructions that we send to the database to get information, manipulate the information or create objects, modify them, and handle the access to the information.

INDEXPROPERTY() function in SQL Database

November 22, 2021 by Rajendra Gupta

This article will give an insight into the INDEXPROPERTY() function in SQL Databases.

SQL Syntax Checker Tools

October 27, 2021 by Esat Erkec

In this article, we will look at the 2 different SQL syntax checker tools that help to find the syntax errors of the queries without executing them.

SQL LEFT function in queries

October 22, 2021 by Esat Erkec

In this article, we will learn how to use SQL LEFT function with straightforward examples.

An overview of SQL Comments

October 19, 2021 by Rajendra Gupta

In a typical database, we have multi lines or page SQL statements in a view, SQL statement or the stored procedure. Also, multiple developers change the T-SQL, and it becomes difficult to track who altered the code and for what reason.

How to write SQL queries with spaces in column names

September 29, 2021 by Nisarg Upadhyay

In this article, we are going to learn how we can write a SQL query with space in the column name. Blanks spaces are restricted in the naming convention of the database object’s name and column name of the table. If you want to include the blanks space in the object name or column name, the query and application code must be written differently. You must be careful and precise while writing dynamic SQL queries. This article explains how we can handle object names and columns with blank space in SQL Server and MySQL.

Popular free SQL online compilers

August 9, 2021 by Hadi Fadlallah

This article will mention some of the most popular free SQL online compilers that help developers debug and test their SQL code without installing an SQL instance locally or buying one on the cloud.

Using Stored Procedures with Return Values

August 6, 2021 by Esat Erkec

In this article, we will learn how we can use a Stored Procedure with return values with all details.

How to write subqueries in SQL

August 3, 2021 by Hadi Fadlallah

This article briefly explains how to write a subquery in SQL by providing examples.

Understanding SQL Server DBCC DBREINDEX command and its usage

August 2, 2021 by Nisarg Upadhyay

In this article, I am going to explain the DBCC DBREINDEX statement, its syntax, and its usage. Additionally, I am also going to cover the differences between the DBCC REINDEX and ALTER INDEX statements.