3 Dec 2024 Jill Thornhill SQL CAST() Function: An Overview The SQL CAST() function converts one data type to another. This article discusses what the function is for, and when and how you’d use it. In relational databases, every column has a defined data type that controls what kind of data is stored in the column and how that data can be used. For example, a product description is likely to be stored as a string of text, and you couldn’t use it for arithmetic (e. Read more 16 Jul 2024 Jill Thornhill PostgreSQL CTE: What It Is and How to Use It CTEs, or Common Table Expressions, are a powerful PostgreSQL tool that’s often ignored. This article looks at various PostgreSQL CTEs – including nested and recursive CTEs – and what you can do with them. If you write complex queries in SQL, you’ll soon find that your code becomes cluttered and hard to read. CTEs – also known as WITH clauses – are primarily a way of simplifying queries. However, they also allow you to use recursion. Read more 11 Jun 2024 Jill Thornhill SQL LAG() Function The LAG() function – one of SQL’s window functions – is an important tool for planning and trend analysis. In this article, I’ll demonstrate how to include SQL LAG() in your queries using a few real-world examples. SQL window functions, also known as analytical functions or OVER functions, add a new dimension to data analysis. They allow you to include aggregates or data from other rows alongside the current row. Read more 30 Apr 2024 Jill Thornhill The SQL MIN() Function SQL has a variety of powerful aggregate tools, including the SQL MIN() function. This article is a quick reference guide to extracting and using minimum values in your queries. In today’s cutthroat business environment, it’s vital to be able to analyze your organization’s data effectively to make informed decisions. SQL’s aggregate functions let you carry out all kinds of statistical analysis on your data. This article is a reference guide to the SQL MIN() function, which extracts the smallest item from a column of data. Read more 19 Mar 2024 Jill Thornhill SQL Aggregate Functions Cheat Sheet A quick reference guide to using SQL aggregate functions. This SQL Aggregate Functions Cheat Sheet is designed to be your companion whenever you’re using SQL for data analysis. Aggregating data is essential for any meaningful data analysis. SQL provides a set of functions that allow you to include totals, averages, and counts in your reports and to extract the minimum and maximum value of any column of data. Read more 13 Feb 2024 Jill Thornhill Integrating SQL with Python for Data Analysis Integrating SQL with Python isn’t difficult. The two tools work together to combine the information-processing power of relational databases with the flexibility of a programming language. In this article, I will discuss the benefits of data analysis using SQL and Python, with real-world coding examples. Why do most of the best data analysis tools on the market – such as Tableau and Power BI – include both SQL and Python in their toolboxes? Read more 10 Jan 2024 Jill Thornhill Data Export: From SQL Query to Spreadsheet How do you export data from an SQL database to Excel or another spreadsheet? In this article, I’ll look at various methods and share a few tips for when things go wrong. SQL is the most widely used method of extracting data from a database. However, it’s not the only gadget in an analyst’s toolbox. Once the information is extracted, you’ll often want to import it into a spreadsheet – maybe to do further analysis or just to make it look pretty so you can present it to management. Read more 7 Nov 2023 Jill Thornhill Why Every Database Administrator Needs SQL What is a database administrator? What do they do? Why do they need to know SQL, and what do they use it for? In this article, I'll answer these questions. As technology advances, more and more data is available to help organizations make informed decisions. You can't stay competitive – or provide good service to your customers – without the right information. Database administrators are responsible for making sure the right data is stored safely, that it's easily accessible to those who need it, and that it’s protected from malicious attacks. Read more 5 Oct 2023 Jill Thornhill BigQuery Window Functions Explained Keeping up with data analysis trends gives your organization – and your CV – the cutting edge. In this article, we'll look at BigQuery window functions and how you can use them to gain deeper insights into your data. Google's BigQuery, launched in 2010, is gaining traction as a popular choice with organizations needing to analyze large quantities of information quickly and to compare their own data against statistical data in the public domain. Read more 15 Aug 2023 Jill Thornhill Data-Driven Career Choices: Database Student Choosing a career is one of the most important decisions you'll ever make. A data-driven career is one of the best ways to secure your future; today's trend is to store and make use of more and more data in every field. In this article, I'll look at some of the choices available. We're living in an era where the quality and quantity of data is expanding exponentially. In almost any career you choose, you'll need to leverage data to make effective decisions. Read more «« « 1 2 » »»