SQL Blog | LearnSQL.com

Monthly SQL Challenges

by Dorota Wdzięczna

10 Jun 2020 SQL learners sometimes need challenges. Do you want to test your problem-solving skills or your knowledge of SQL? Then take our monthly SQL Challenges! We prepare them on LearnSQL.com every month. Each Challenge relates to a different interesting topic and will help you keep your SQL game sharp. In this article, you'll discover what our LearnSQL.com Monthly Challenges are and where to find them. We’ll also look at the Challenges collected in our Monthly SQL Challenge Mini Track.

Practical Examples of When to Use Non-Equi JOINs in SQL

by Kateryna Koidan

9 Jun 2020 If you think that two tables in SQL can be joined only using the common field, you will be excited to learn that there are other ways of joining. Non-equi JOINs use different kinds of comparison operators in the JOIN condition. In this article, I’ll guide you through non-equi JOIN examples to show the common use cases for this type of JOIN. Equi JOIN vs. Non-Equi JOIN How do you usually join two tables in SQL?

SQL Course of the Month - SQL Practice Set

by LearnSQL.com Team

5 Jun 2020 It is said that practice makes perfect. I agree with this statement one hundred percent. What is applicable in basketball training, playing an instrument, or learning a foreign language is also useful in learning SQL. Practicing writing queries, using functions, and putting together clauses is the basis for learning the true power of SQL. But how and where do you practice SQL? I spoke with Agnieszka Kozubek-Krycuń, Chief Content Officer at Vertabelo about this.

How to Convince Your Boss That You Need to Start Learning SQL

by Pierre Timms

4 Jun 2020 Learning SQL is a great goal. Now, if you could only convince your boss that it’s good for the company as well as for you ... You’re aware of the benefits of adding SQL to your skill set. You believe that the rewards gained from you learning SQL will also benefit your employer – it’s not just another way for you to develop your professional profile. But how do you articulate this to your boss?

Top 5 Programming Languages to Learn Alongside SQL

by Rebecca McKeown

3 Jun 2020 If you already know or are about to learn SQL, you’re well on your way to being a sought-after database administrator, database engineer, or just a general database whizz kid! SQL is a modern, widely-used language that finds application in almost every industry. There is no shortage of jobs with SQL. But what if you want to branch out and learn another language to complement your SQL knowledge and skills?

How to Learn SQL JOINs

by Zahin Rahman

2 Jun 2020 JOINs are one of the most fundamental and commonly used SQL commands for manipulating and querying real-world data sets. They are also one of the more challenging SQL topics to master! In this article, you’ll learn an effective strategy to learn the different types of SQL JOINs. When data is stored in a single table, we can easily retrieve rows and get all the information we need. But when businesses scale, so does their data.

New Monthly Challenge!

by LearnSQL.com Team

1 Jun 2020 The new LearnSQL.com Monthly Challenge is ready! In June, we invite you to use your SQL skills to analyze insurance agency activities. Is this the first time you’ve ever come across our Monthly Challenge? Then you should know that it’s a set of 5 to 10 SQL exercises prepared for people who want to practice what they’ve learned. Each challenge is designed around a specific theme. In this seventh challenge, the exercises are built around a fictional insurance agency, but in the other challenges we’ve explored the subjects of pizza, the stars, a car workshop, and bakery management.

What Are the Different Types of SQL Subqueries?

by Kateryna Koidan

29 May 2020 Subqueries can be used in many business cases. What subquery types does SQL offer? And how can you use them efficiently? In this article, I’ll guide you through different subquery types and the typical situations when they are useful. What Is an SQL Subquery? A subquery, or nested query, is a query placed within another SQL query. There are many different scenarios where you may want to include a query in the WHERE, FROM, or SELECT clauses of your main query.

Subquery vs. JOIN

by Dorota Wdzięczna

28 May 2020 One of the challenges in writing SQL queries is choosing whether to use a subquery or a JOIN. There are many situations in which a JOIN is the better solution, and there are others where a subquery is better. Let’s consider this topic in detail. Subqueries are used in complex SQL queries. Usually, there is a main outer query and one or more subqueries nested within the outer query.

5 Advanced SQL Constructions Every Data Analyst Should Learn

by Tihomir Babic

27 May 2020 Does your job involve data analysis? Here are five examples of how advanced SQL can help you in your daily work. I’m a data analyst and I have to say – data analysts can be quite strange. Other people are usually afraid of immense amounts of data; we enjoy it. The deeper we get into data, the happier we are. An important tool for getting into data (and thus being a happier data analyst) is SQL.

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