SQL course

We provide three options for learning SQL. Here you will find our free article-based SQL language course. This consists of a number of articles that will get you started in your journey to learn SQL. If you are looking to go into more detail, practice with worked examples and elevate your skills to an expert […]

SQL (Structured Query Language) is a powerful tool for managing and querying relational databases. One of the fundamental operations in SQL is the SELECT statement, which allows you to retrieve data from a database. In this article, we will explore how to use SQL SELECT statements to retrieve, sort and filter data. We will look

In SQL, grouping data is a powerful operation that allows you to aggregate and analyse data effectively. This is especially useful when you want to generate aggregated data or perform calculations. You can also filter the returned aggregations based on the aggregated results rather than individual row details.  This cannot be done with the WHERE

Subqueries, sometimes referred to as nested queries or inner queries, are a useful feature in SQL that allows you to deal with more complex data retrieval and manipulation tasks. They are a useful tool for any SQL developer or database administrator, enabling you to write more sophisticated queries. This article will provide an in-depth understanding

So far we have largely looked at selecting data from a single table. In this article, we will look at how data can be combined from multiple tables with the use of SQL joins. There are different ways of joining data together including the INNER JOIN, LEFT OUTER JOIN, RIGHT OUTER JOIN, FULL OUTER JOIN

In this guide, you will learn the syntax and see some practical examples of how to use the SQL insert data command. We will introduce some new Keywords including INSERT INTO and look at how you can insert a single or multiple rows. SQL Insert data table of contents Learn SQL online For our instructor

In this article, we will explore how to update and delete data using SQL, providing both theoretical insights and practical examples to help you become proficient in these essential database tasks. Updating allows you to modify existing records while deleting allows you to remove unwanted data from your database. You should always exercise caution when

 In this article, we will explore the process of creating and altering tables in SQL Server, including an explanation of data types, practical examples, and best practices. In a relational database, data is organized into tables. Each table comprises rows and columns, where each row represents a unique record, and each column defines a specific

SQL views are virtual tables that provide a way to simplify complex queries and enhance data security by limiting access to specific columns or rows of a table. Views can be used by external reports or applications to save other developers from having to deal with some of the complexities of data extraction. In this

Working with a Stored Procedure / SPROC is considered an advanced skill in SQL development. Sometimes a stored procedure is abbreviated to sproc. Stored Procedures / SPROCs are precompiled SQL statements that can be executed in a controlled manner. They can accept input parameters, output parameters and a single return value. They are similar to