18 Apr 2024 Tihomir Babic GROUP BY and Aggregate Functions: A Complete Overview SQL’s GROUP BY and aggregate functions are essential in data aggregation – and for analyzing data and creating reports. Let’s explore them together! In SQL, GROUP BY and aggregate functions are one of the language’s most popular features. Data aggregation is critical for data analysis and reporting; to make sense of all the data in a dataset, it often needs to be aggregated. But what is data aggregation? Put simply, it’s when you group data based on common values and perform a calculation for each data group. Read more 21 Mar 2024 Tihomir Babic 15 Tricky SQL Interview Questions for Experienced Users SQL interview questions for experienced users usually contain some trick(y) questions. Interviewers use them to test your gumption, which is typically a result of extensive experience and a high level of SQL knowledge. I will show you 15 tricky SQL interview questions (mostly coding) in this article. Mind you, these are not necessarily complex questions. Actually, that’s their main characteristic: they seem very easy and straightforward, but that’s the interviewer trying to deceive you. Read more 8 Feb 2024 Tihomir Babic 9 Practical Examples of SQL LEFT JOIN LEFT JOIN is one of SQL's most common JOINs. Make sure you know all its ins and outs by going through all nine of our real-life LEFT JOIN examples. LEFT JOIN – alongside INNER JOIN – is one of the essential SQL tools you need to work with data from two or more tables. But how and when should you use it? These nine LEFT JOIN examples will point the way. Read more 30 Jan 2024 Tihomir Babic SQL Server Date Functions: A Data Analysis Guide Date functions are the bread and butter of data analysis and reporting with SQL Server. In this guide, I will show you practical examples of the use of SQL Server date functions and how to apply them to your reports. A question for all data analysts: Do you want to be taken seriously? I’m sure you do. In that case, knowing SQL Server date functions is mandatory. Date and time data types are ubiquitous in databases, as they are essential for reporting. Read more 26 Dec 2023 Tihomir Babic Basic SQL Query Practice Online: 20 Exercises for Beginners These 20 exercises are just what beginners need for SQL query practice. Try to solve each of them, and then look at the solutions. If something needs to be clarified, there are explanations for each solution. In this article, there’ll be less talking than usual. Instead, you’re going to write the answers to SQL practice queries. (Don’t worry; we’ve included the solutions if you get stuck.) The whole point is to give you, as a beginner, plenty of opportunities for SQL query practice. Read more 28 Nov 2023 Tihomir Babic What Are SQL Window Functions? Need to up your data analysis game? Learn these SQL window functions here and you’ll take your analysis skills to the next level. Practice exercises and detailed explanations included! When I first heard about SQL window functions, I thought it was some strange marriage between SQL and Windows. I was wrong. The SQL window functions have nothing to do with that famous operating system. They are SQL functions that do computations on the set of rows related to the current row. Read more 19 Oct 2023 Tihomir Babic Top 29 SQL Server Interview Questions Looking for an SQL Server job? Review these 29 must-know SQL Server interview questions and you’ll be well-prepared. And don’t worry about looking up the answers – we provide them, too! Microsoft SQL Server's first version was released in 1989 and has a rich history. It has come a long way since then, becoming one of the most used database engines in the data industry. In the last ten years, it’s been the third most popular database engine. Read more 21 Sep 2023 Tihomir Babic What Is FULL JOIN in SQL? An Explanation with 4 Examples What is FULL JOIN – one of the often neglected SQL join types? In this article, we’ll show you how useful FULL JOIN can be and teach you how to apply it to different scenarios. The four examples cover some of the typical uses. An SQL join is a construction for combining data from two or more tables. FULL JOIN is one of the types of joins. You’ll get the most from this article if you’re already familiar with SQL joins and how they work. Read more 5 Sep 2023 Tihomir Babic SQL Joins: 12 Practice Questions with Detailed Answers In this article, we dig into our SQL JOINS course and give you 12 join exercises to solve. But don’t worry – all the exercises have solutions and explanations. If you get stuck, help is there! This is, after all, made for practicing and learning. SQL joins can be tricky. It’s not just the syntax, but also knowing what joins to use in what scenarios. Joins are used when combining data from two or more tables in SQL. Read more 17 Aug 2023 Tihomir Babic 20 Basic SQL Query Examples for Beginners These 20 basic queries are a must in a starter pack for every SQL beginner. These examples will get you going on your journey to mastering SQL. You’ve set your mind on learning SQL, googled ‘basic sql query examples’ or something similar, and here you are staring at this article. Now what? All learning starts with the basics, so let’s start with the most basic question: What Is SQL? Read more «« « 1 2 3 … 8 » »»