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 7 Jun 2022 Tihomir Babic How to Combine Two Aggregate Functions in SQL Having trouble using two aggregate functions in one query? This article will show you how to do it the right way – actually, the two right ways. In data analysis and reporting, we often need to count the number of records or sum them up and then calculate the average of this count or sum. Translated to SQL logic, this is the aggregation of aggregated data, or multi-level aggregation. For aggregation purposes, there are the SQL aggregate functions. Read more 17 May 2022 Tihomir Babic Top 9 SQL GROUP BY Interview Questions Preparing for an SQL job interview? This guide will walk you through nine basic, intermediate, and advanced GROUP BY questions that you may have to answer. There are common GROUP BY questions that pop up in a lot of SQL job interviews; in this article, we’ll explain how to answer them. If you are a data analyst or another data professional preparing for an interview, this article aims to help you out. Read more 12 May 2022 Tihomir Babic What Are Window Functions in SQL? In this article, we discuss what window functions are and how they help you do your job as a data analyst or specialist. No, window functions have nothing to do with the operating system. The window here refers to a set of rows over which the function aggregates data. To learn how window functions work, what functions there are, and how to apply them to real-world problems, it’s best to take the Window Functions course. Read more 24 Mar 2022 Tihomir Babic How to Write Multiple CTEs in SQL Leverage the full potential of the CTE by combining two or more of them in a single SQL query. Common table expressions, or CTEs, can be a powerful SQL tool. When you write two (or even more) CTEs together, this power multiplies. In this article, I’ll show you three ways of writing multiple CTEs: Using two independent CTEs in one SQL query. Using two CTEs where the second CTE refers to the first. Read more 22 Mar 2022 Tihomir Babic The SQL Substring Function in 5 Examples Working with text data in SQL? We explain how to get values from any point in a string. When you think of working with data in SQL, your first thought is probably a database full of numbers and your SQL code doing very fancy calculations. But text is data, too! It’s very common to find text data in databases. Not only do you have to extract it, but often you also have to manipulate it. Read more «« « 1 2 3 4 5 … 9 » »»