10 Nov 2022 Tihomir Babic How to Use GROUP BY in SQL In this article, we’ll give you a step-by-step guide on using GROUP BY in SQL. Uncover the nuances of the GROUP BY clause and learn different ways of using it. GROUP BY is one of the most-used clauses in SQL. It moves you from simply selecting data from the database to grouping rows with the same column values into one group. When used with SQL’s aggregate functions, you can use GROUP BY to compute metrics like counting the number of instances or finding the total, average, minimum, or maximum value. Read more 8 Nov 2022 Tihomir Babic How to Use the PARTITION BY Clause in SQL We’ll be dealing with the window functions today. Specifically, we’ll focus on the PARTITION BY clause and explain what it does. PARTITION BY is one of the clauses used in window functions. In SQL, window functions are used for organizing data into groups and calculating statistics for them. It sounds awfully familiar, doesn’t it? Even though they sound similar, window functions and GROUP BY are not the same; window functions are more like GROUP BY on steroids. Read more 25 Oct 2022 Tihomir Babic An Overview of SQL Text Functions in PostgreSQL If you’re a PostgreSQL user and into data analysis, you’ve heard of the text functions or maybe even used them. But what are PostgreSQL’s most popular text functions? In today’s article, we’ll show you what they are and how to use them. As anyone who works with them knows, databases don’t contain only numerical values. Among other data types, databases also store text or string data. To use PostgreSQL effectively, you’ll have to know at least some of Postgres’ text functions. Read more 10 Oct 2022 Tihomir Babic SQL Courses for Software Testers In this article, you will learn why software testers need SQL and which courses are ideal for them to learn it. Do software testers need SQL? Oh yes, they do! They don’t necessarily use it all the time or take advantage of all its possible features. But a tool for accessing data in a database is essential for a software tester. And SQL is exactly that: a programming language designed specifically for handling data in relational databases. Read more 13 Sep 2022 Tihomir Babic Top 10 MySQL Interview Questions And Answers You learned SQL and now you want to use this valuable skill to get a better job. Now it’s time to prepare for the job interview. We’ve got ten MySQL interview questions and answers to help you with that. In today's hyperconnected world, knowing how to deal with it has become a necessary skill. That’s why you probably learned (or want to learn) SQL: either your job requires it or you realized that you need SQL to get a better job. Read more 8 Sep 2022 Tihomir Babic SQL Syntax In today’s article, we’ll give you a walkthrough of core SQL syntax with a focus on the SELECT, INSERT INTO, UPDATE, and DELETE statements. SQL is a programming language designed specifically to communicate with databases. It allows you to get the data from a database or change the data within it. Like any programming language, SQL has a syntax you must adhere to. In other words, there are rules to follow regarding its commands if you want your code to work. Read more 18 Aug 2022 Tihomir Babic An Overview of SQL Text Functions in Google BigQuery Data analysts and Google BigQuery go hand in hand. Google's cloud data warehouse presents you with plenty of opportunities for using standard SQL text functions you can't avoid in your day-to-day work as a data analyst. BigQuery uses Google Standard SQL, an ANSI-compliant SQL dialect. This means you can use standard SQL text functions in BigQuery without needing to learn a variant of a given function. The Standard SQL Functions course is an excellent resource for learning those functions. Read more 11 Aug 2022 Tihomir Babic How to Use Aggregate Functions in WHERE Clause Filtering data according to the result of an aggregate function is a common data analysis task. So how do you use aggregates in the WHERE clause? We’ll dedicate this whole article to answering that question. Combining aggregate functions and filtering based on their results is often used in data analysis – e.g. showing branches with total sales above X, countries where the number of posts is lower than Y, students with an average score below Z, and so on. Read more 7 Jul 2022 Tihomir Babic An Overview of SQL Text Functions in MySQL Do you work in MySQL as a data analyst? Then you should know how to use its text functions – data analysts don’t work only with numbers. Reporting requires computations, data classification, and label creation, and you can do all of that in MySQL. In this article, I’ll explain several of the most common and useful MySQL text functions by discussing what they do and showing how they do it. Read more 23 Jun 2022 Tihomir Babic An Overview of Microsoft SQL Server Text Functions Data analysts use text values when creating SQL reports. You can create your own labels with functions, classify rows based on text value, or do computations based on it. This article covers how to do all that. The text values in databases are not just for reading. As with numeric values, we perform operations on them and manipulate the text. SQL Server has a fair number of text functions. Read more «« « 1 2 3 … 7 » »»