Articles Cookbook
17 Sep 2024
Martyna Sławińska

12 SQL Functions Practice Questions

SQL functions allow us to manipulate data, including string and numeric values. This article presents 12 SQL functions practice questions – with solutions and detailed explanations – that will help you solidify your SQL knowledge. Practicing SQL is important if you want to improve your skills. But finding SQL practice exercises is hard. We want to help, so we’ve been publishing free compilations of SQL practice exercises. In this article, we’ve provided 12 SQL functions practice questions, complete with solutions and explanations.
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12 Sep 2024
Alexandre Bruffa

Top 5 Reasons PostgreSQL Works for Data Analysis (and Data Analysts!)

Why do analysts love PostgreSQL for data analysis? Learn why this database management system is so beloved of database professionals and data scientists alike! If you work with data, you know that data analysis requires the efficient storage, management, and retrieval of large datasets. Thus, data analysts prefer to use relational databases that are well-known for their robustness, efficiency, and stability. Relational databases work with a database management system (DBMS), which allows the creation, management, and manipulation of relational databases.
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10 Sep 2024
Gustavo du Mortier

The MySQL CTE and How to Use It

Common table expressions (CTEs) in MySQL give even more versatility to this popular database management system. Find out how to use CTEs to simplify complex queries and implement recursion. All programming languages have ways of simplifying problems by breaking them down into parts that can be solved individually. Users can unify the partial results to obtain a single final result. Thanks to something called common table expressions (CTEs), MySQL is now exception.
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5 Sep 2024
Michał Wasiluk

A Guide to PostGIS: Basic Geospatial Data Query Examples

Geospatial data is becoming increasingly important in many fields, from urban planning to environmental science. In this article, we’ll demonstrate basic PostgreSQL PostGIS queries for working with this type of data. Geospatial data, which contains information about locations on Earth, requires specialized tools for effective use. PostGIS is a powerful PostgreSQL extension that turns a Postgres database into a full-featured Geographic Information System (GIS). With PostGIS, you can store geographic objects, run spatial queries, and perform advanced analyses directly in SQL.
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3 Sep 2024
Owen Brock

How the "SQL Basics" Course Boosted My Productivity

As a data analyst, switching from Excel to SQL was a game changer. In this article, I'll show you how completing LearnSQL.com’s SQL Basics course improved my productivity. As a data analyst, I rely on data to analyze and plan my team’s workloads and deliveries. For years, I mostly used Excel for this – but as the amount of data grew, it became harder and harder to manage everything manually.
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1 Sep 2024
LearnSQL.com Team

Course of the Month: SQL Practice Set in PostgreSQL

Do you know the basics of PostgreSQL but still need some practice? Look no further! Here is a great interactive course, SQL Practice Set in PostgreSQL. Throughout the month of September, you have access to it for FREE! We at LearnSQL.com believe that to learn a new skill, you need basic theoretical knowledge and, above all, a lot of practice. It's the same with writing PostgreSQL queries – you need a lot of PostgreSQL practice.
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30 Aug 2024
LearnSQL.com Team

New Monthly SQL Practice for September 2024!

Ready for our new SQL challenge? This time, the tasks are slightly more difficult. In this course, you will assist MoMA’s management by analyzing data using standard SQL functions to answer questions and solve problems. Welcome to the September SQL Practice course! In our September 2024 SQL Practice, you will work with the database at the Museum of Modern Art (MoMA) in New York City. MoMA’s management has hired you, an SQL specialist, to bring a fresh perspective to the museum.
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29 Aug 2024
Ekre Ceannmor

How to Export Data from PostgreSQL into a CSV File

Do you need to quickly send data to a client or share a report for further analysis? A CSV file is a great sharing option! Let’s take a look at how you can use this format to export data from a PostgreSQL database. In this article, we will first review what the CSV file format is and why it’s handy when exporting your PostgreSQL database. Then we will export some example data from a real database using psql on the command line and pgAdmin, a free and open-source interface for PostgreSQL databases.
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27 Aug 2024
Jakub Romanowski

Top YouTube Channels Every Data Analyst Should Follow

If you're a data analyst or looking to become one, YouTube is a great resource to help you learn and grow. In this article, I’ll share the top YouTube channels every data analyst should follow. These recommendations will give you the knowledge you need to succeed in data analysis. YouTube is a great place to start learning data analysis, and I’m here to help you get the most out of it.
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22 Aug 2024
Michał Wasiluk

An Introduction to Spatial Databases and Geospatial Data

Discover how spatial databases and geospatial data enhance spatial queries, support GIS integrations, and enable advanced data analysis. Spatial databases are specialized database systems designed to store, manage, and query geospatial data efficiently. These databases provide support for spatial data types and spatial indexing, allowing for complex spatial queries and analysis. Geospatial data, stored within these databases, represents information about the physical world tied to specific locations on Earth.
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