Articles Cookbook
20 Jan 2022
Andrew Bone

10 PostgreSQL Interview Questions and Answers

Job interviews are always stressful. Interviewing and getting asked technical questions about PostgreSQL is even more of a challenge! In this article, we’ll cover some of the PostgreSQL interview questions you can expect when applying for a new job. By the end of the article, you should be able to handle most of the questions you are likely to face. We’ve previously covered common questions you can expect at a SQL job interview, but this article will be focused on Postgres specifically.
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19 Jan 2022
Ignacio L. Bisso

What Is a Common Table Expression (CTE) in SQL?

The common table expression (CTE) is a powerful construct in SQL that helps simplify a query. CTEs work as virtual tables (with records and columns), created during the execution of a query, used by the query, and eliminated after query execution. A CTE is defined using a CTE query definition, which specifies the structure and content of the CTE. CTEs often act as a bridge to transform the data in source tables to the format expected by the query.
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18 Jan 2022
Kamila Ostrowska

The Top 5 SQL Courses and Learning Platforms for 2025

It’s the New Year! Time to start thinking what good you can do yourself in 2025. If you haven’t decided yet, we want to recommend learning something new – specifically, learning SQL. Thinking about learning SQL this year? If so, don’t waste time—SQL can open new career opportunities and even transform your future! To get the most out of your learning, it’s crucial to choose courses that match your goals.
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13 Jan 2022
Karolina Niewiarowska

Top 10 Beginner Online SQL Courses in 2022

Ready for New Year’s changes? Good, because now you have a perfect chance to achieve something new: Improve your skills by learning SQL! In this article, we’ll point you toward some great online SQL courses to help you meet this goal. SQL, or Structured Query Language, is the language used to communicate with relational databases. When you know SQL, you can add, delete, change, and make calculations using the data in a database.
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11 Jan 2022
Himanshu Kathuria

The Most Popular Databases for 2022

With the number of database products increasing with each passing year, it is important to understand which database best fits your use case. This article lists the top-ranking databases available in the market today. When something that first became popular in the early 1980s is not slowly fading away but is still evolving and becoming more relevant, you know it had to be an important invention. The database is no exception.
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30 Dec 2021
Tihomir Babic

How to Include Zero in a COUNT() Aggregate

Explaining how to include zero (0) counts in your SQL query result. Here’s the problem: you want to count something that doesn’t exist, and you want to show your result as zero. How do you do that in SQL? Using the COUNT() aggregate function is a reasonable first step. It will count all the data it finds and return the number of occurrences. But what if there are no occurrences of certain data?
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28 Dec 2021
Karolina Niewiarowska

Here’s How I Started Creating SQL Reports

Once upon a time, there was a girl who was just starting her adventure with learning SQL. As a marketer, one of her tasks was writing reports. Previously, she used Excel, a calculator, and written notes to prepare the reports her boss required. One day, it turned out that she could do her job much faster and easier. That was the day she read about SQL reports for the first time.
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23 Dec 2021
Ignacio L. Bisso

How to Use the SQL PARTITION BY With OVER

At the heart of every window function call is an OVER clause that defines how the windows of the records are built. Within the OVER clause, there may be an optional PARTITION BY subclause that defines the criteria for identifying which records to include in each window. Read on and take an important step in growing your SQL skills! What Is the PARTITION BY Clause in SQL? The SQL PARTITION BY expression is a subclause of the OVER clause, which is used in almost all invocations of window functions like AVG(), MAX(), and RANK().
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16 Dec 2021
Kamil Bladoszewski

Is SQL Case-Sensitive?

Is SQL case-sensitive? The question seems simple, and you may think it’s a yes-no question. However, the answer depends on multiple factors. Let’s take a look at the possible answers. First of all, this question can be understood in multiple ways. Which part of SQL are you asking about? Do you mean keywords (e.g., SELECT, WHERE, etc.), table and column names, or values in the columns? Which database management system (DBMS) do you have in mind?
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14 Dec 2021
Jakub Romanowski

Top 5 MS SQL Server Courses for Beginners

Every journey, including a career change, begins with the first step. If you're thinking about learning data analysis or strengthening your MS SQL Server skills arsenal, you've come to the right place. Here are the top 5 MS SQL Server online courses. Enjoy! You've probably heard that today’s organizations rely heavily on data analysis. You heard right. They are looking for employees who can navigate the world of databases and draw conclusions from data.
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