Articles Cookbook
20 Dec 2016
Adrian Dembek

6 Common SQL Syntax Mistakes All Learners Make

Updated on: June 22, 2024 We all make mistakes when learning a new language – especially at the beginning. New words, complicated grammar... Everyone needs time to master a language. But when we get immediate feedback, we can progress more quickly. The same goes for learning SQL. In this article, we'll look at 6 common SQL syntax mistakes most SQL learners make. Learning SQL can feel like deciphering a complex code, especially when you’re just starting out.
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19 Dec 2016
Marcos Pierri

8 Tips Absolute Beginners Can Use to Fix SQL Queries

Code errors are common – and frustrating. And when you're just learning SQL, it can be very challenging to find and fix your mistakes. In this post, we'll show you eight ways to solve or eliminate common SQL coding errors. Today, we'll talk about some tips the SQL beginner can use to avoid several common errors. These tips work in any database environment. As we go along, we'll be showing some error messages.
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13 Dec 2016
Aldo Zelen

How to Learn SQL: 6 Ideas for Newbies

Learning a new skill can be a daunting task, especially in programming. SQL is not immune to this. Luckily, with the Internet and the explosion of programming-related information out there, there are a lot of options you can use to undergo your SQL training! But we then come to a new roadblock. Where to begin? How will we know which option is best for our budget, skill level, and schedule?
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13 Dec 2016
Maria Alcaraz

Correlated Subquery in SQL: A Beginner’s Guide

Sometimes, using a SQL correlated subquery is the only way to solve a statement. But these subqueries can be very slow. In this post, we’ll talk about when to use a correlated subquery, why, and how to do it. Subqueries are an important resource for increasing the expressive power of SQL. If you haven’t read our previous article, subqueries are simply a SELECT statement inside another SELECT. We can use them in different places inside a SELECT, such as in the WHERE, HAVING, or FROM clauses.
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6 Dec 2016
Aldo Zelen

Five Common SQL Syntax Errors

Updated on: July 19, 2024 SQL is a powerful language for managing databases, but even small syntax errors can lead to big headaches. As you work with SQL, understanding and avoiding common mistakes can save you time and frustration. In this article, we'll highlight five frequent SQL syntax errors You've written your SQL code and you're ready to query your database. You input the code, but instead of getting the data you expected, you get an error message.
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6 Dec 2016
Aldo Zelen

SQL Errors: Five Common SQL Mistakes

As you learn SQL, watch out for these common coding mistakes You’ve written some SQL code and you’re ready to query your database. You input the code and …. no data is returned. Instead, you get an error message. Don’t despair! Coding errors are common in any programming language, and SQL is no exception. In this article, we’ll discuss five common mistakes people make when writing SQL. The best way to prevent mistakes in SQL is practice.
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26 Nov 2016
Michał Kołodziejski

Do it in SQL: Recursive SQL Tree Traversal

In the previous article, I described how to use Common Table Expressions to find the shortest path in a directed graph. That example could be hard to follow, I admit. Let’s do something much more common, something that is implemented on almost every website – a menu. Instead of writing the code, we’ll take advantage of the SQL tree structure writing just one query. We’ll use CTEs for PostgreSQL and the hierarchical query clause for Oracle.
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21 Nov 2016
Patrycja Dybka

SQL JOINs Explained with Venn Diagrams

A SQL JOIN is a method to retrieve data from two or more database tables. This article presents a basic overview of what data from a particular SQL join will look like. A popular way of understanding SQL joins is to visualize them using Venn diagrams, so each example have corresponding Venn diagram, appropriate SELECT statement and the result table. There are a few major kinds of SQL joins:
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18 Nov 2016
Patrycja Dybka

SQL Subqueries

The article describes what a subquery is and what these useful statements look like. We will cover basic examples with the IN, EXISTS, ANY, and ALL operators, look at subqueries in FROM and WHERE clauses, and explore the difference between correlated and nested subqueries. First, let’s start with an example database. To present some of these statements we need to have an example table and fill it with some data.
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25 Oct 2016
Adrian Dembek

SQL JOINs for Beginners

You’re probably already familiar with simple SQL queries, such as SELECT * FROM table. Now you are wondering what to do when you have multiple tables, and you want to join them. Exactly! JOIN is the key. In this SQL JOINs tutorial for beginners, you will learn how to connect data from multiple tables. What are SQL JOINs? Databases usually have more than one table. JOINs are an SQL construction used to join data from two or more tables.
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