SQL is not a traditional programming language in which you write a sequence of instructions in a given order of execution. Instead, SQL is a “declarative” language, which means that by writing a SQL query, you declare what data you expect as a result of the query, but you don’t indicate how to obtain it. Six Operations to Order: SELECT, FROM, WHERE, GROUP BY, HAVING, and ORDER BY By using examples, we will explain the execution order of the six most common operations or pieces in an SQL query.
SQL is replacing Excel in many fields, and data analysis is certainly one of them. If you are still using Excel as a data analyst, you are missing something very valuable. SQL can make your life easier, as it’s more efficient and faster than Excel. So, how and from where can you learn SQL? How Can SQL Help Data Analyst? You can use SQL to help you with the following work:
Data science is hot right now. If you want to learn more about it, where should you go? Online, of course! Check out our favorite data science sites. Whether you’re a beginner or a pro, these are the sites you should know. Not so long ago, if you wanted information on a topic like data science, you had to look for it—either at your local library or at a university.
How do you get data from a table? How do you create or delete a table? How do you display distinct records? How do you select rows which store a specific value in a column? You can easily do all of this by writing basic SQL queries. This guide discusses the 30 most important SQL queries for beginners. Let’s take a look. 1. Retrieving Data From All Columns This is a very basic query to display all data from a table.
Already know some SQL basics and want to take your PostgreSQL skills to the next level? Learn how to create, use, and manage your own functions in PostgreSQL. We’re pleased to announce the launch of our new online course: Writing User-Defined Functions in PostgreSQL. This course is aimed at people who already know some basic SQL and greatly benefits not only PostgreSQL developers and database administrators but also anyone interested in database programming (especially through PostgreSQL).
YouTube is not just funny cats, music clips, and viral videos. It can also be a mine of knowledge – if you know where to look. Can YouTube tutorials really help you learn SQL? Let's say you're a marketer or an accountant. You work with databases every day. But when it’s time to write a query and get specific data, you need to call someone from IT. Why not learn to do it yourself?
Writing queries to a database requires knowledge about SQL syntax, but this is not all you should know. Best practices for writing professional SQL code require good formatting skills. In this article I discuss why this is so important and what are the basic rules you should follow. Why is it Worthwhile to Format SQL Code? Beginner SQL programmers often don't pay much attention to formatting their code. If you think formatting is something that can be safely ignored, look at the code below:
How do you visualize the results of an SQL query? You usually need to use multiple tools to achieve that. Why not use a tool that communicates with SQL directly and can perform any data analysis task? R is a data-oriented programming language that uses packages (libraries) to help you with nearly every imaginable data analysis task and more. Some of these packages allow R connect to an SQL database so you can query it and perform any desired action on the result set.
In this article, I will cover perhaps the most important element of the SQL language. That's right! I'm talking about the SQL INNER JOIN clause. As you know, in a database the data are stored in several tables. In my last article, I covered how to create SQL queries when the data you need is in only one table. But what if the data you need is in two tables?
Find out why you should forget about Excel and start using SQL even if you’re not an IT expert. We’ll show you how easy it is to learn SQL, how it can make you work better, and how Vertabelo Academy makes the learning process fun. “I Don’t Deal With Data” We frequently hear the sentence above from people outside the IT industry. Well, it’s not entirely true. Data is now almost everywhere.
Learn how the T-SQL data manipulation language (DML) can help you control the information inside your SQL Server database. Do you work with SQL Server? Interested in learning more about the T-SQL language? Then you’re in the right place! We’re excited to introduce our new online course: How to Insert, Update, or Delete Data in MS SQL Server. In this course, you’ll learn about the data manipulation language (DML) statements in T-SQL.
If you’re looking for an online course to improve your SQL skills for Microsoft SQL Server or simply want to pass the Microsoft SQL certification, you’re in the right place. Vertabelo Academy’s new course—GROUP BY Extensions in MS SQL Server—is a perfect way to learn how to create advanced reports or facilitate ETL processes. At Vertabelo Academy, you’ll find lots of general SQL courses that’ll teach you to work with any relational database.
So you want to learn SQL and decided to learn with Vertabelo Academy? That's great! This article show you the sequence in which to take the courses in order of increasing difficulty. Courses Teaching Standard SQL (ANSI) If you plan to begin learning SQL and would like to become a professional, your first step is to complete the SQL Basics course. This is the fundamental course that will provide a smooth introduction to the world of relational databases by learning about tables.
Level: Advanced Most commonly, the SQL queries we run on a database are quite simple. Well, that depends on your role, of course. Analysts in data warehouses retrieve completely different sorts of information using (very often) much more complicated queries than software engineers creating CRUD applications. However, sometimes it’s simpler or more elegant to run a query that is a little bit more sophisticated without needing further data processing in the code.
Brush up on your data science and SQL skills with Vertabelo Academy’s interactive courses. Why Vertabelo Academy? You get instant access to lessonsthat teach various concepts of SQL, data science, and programming in R (soon also in Python!). Our courses are appropriate for people who have no prior knowledge of computer science or programming. The only requirement is a web browser. No need to install databases, download example tables, or spend time inventing exercises for yourself.