Autor: Codenga 14.05.2024

Learn about SQL, its applications, professions requiring SQL knowledge, and ways to learn this language.

SQL is a language used to manage relational databases. With its help, you can manipulate data freely. SQL enables various operations in a database:

• creating tables,
• inserting data,
• reading data,
• deleting data,
• managing database configuration.

In practice, working with SQL involves writing appropriate queries. Each operation has its characteristic queries. For example, if you want to read data, you write the appropriate query to the database.

Varieties and Versions of SQL

There are various varieties of databases that use the SQL language. Here are a few examples:

MySQL

MySQL is a very popular database, relatively easy to use. It has good documentation and a wide user community.

PostgreSQL

A modern and advanced database based on the SQL language. It is often chosen as an efficient alternative to MySQL.

Microsoft SQL Server

This database is commonly used in Microsoft tools. It is often used in corporate and business environments.

SQLite

A lightweight database in the form of a single file. Used, for example, in mobile applications and wherever a relatively simple database is needed. You can find more about SQLite in this article.

The above databases may differ in details, but they all are based on the SQL language. This means that knowledge of this language will be useful for working with any of the databases mentioned above.

In Which Jobs Is SQL Knowledge Needed?

SQL-based databases are used in many fields. Below are examples of popular professions that require knowledge of this language:

• Database Administrator - responsible for maintaining and developing databases.
• Data Analyst - uses the database to analyze data and draw conclusions.
• Application Programmer - creates applications storing data in SQL databases.
• Data Engineer - designs and develops systems for storing data.

These are just a few examples of professions requiring SQL knowledge for work. This language is very widespread. It is often encountered, for example, in applications from the Microsoft Office ecosystem - a good example is the popular Access program.

It is also worth considering the subject from the perspective of entire fields, not just individual professions. SQL is used in statistics, marketing, management, accounting, and many other fields.

Difficulty Level of SQL

SQL is a relatively simple language, especially compared to typical programming languages such as Java, C++, or C#. It can be said to be beginner-friendly.

Basic Level

Basic SQL can be mastered in a few days. Such a level is sufficient for writing simple queries to read data from the database. In many professions, these skills are entirely sufficient.

Intermediate-Advanced Level

If your work requires knowledge of SQL at a higher level, be prepared for longer learning, typically counted in months.

Expert Level

SQL specialists usually have many years of experience. We're talking about people who deal with data security, performance optimization, or database access management.

How to Start Learning SQL

To begin with, you need to learn the basic queries for reading data from the database. In SQL, we use the SELECT query for this purpose. Filtering, grouping, and sorting data are also often applied. All these operations must be well mastered to proceed with further steps in learning.

The best way to learn is through practice and regular exercises. SQL is a very practical field - real skills are more important than deep theory. You need to practice writing queries, preferably on a real database.

SQL Courses

Online courses are the optimal way to learn SQL. They usually offer a good cost-to-effect ratio. Try to find those that, in addition to theory, offer the opportunity to practice skills in practice.

There are also other methods - self-study, books, classroom training. SQL is a popular topic, and there is no shortage of appropriate training materials.

SQL Certifications

In some industries, certifications confirming your SQL skills may be useful. Employers sometimes explicitly require a specific certificate from candidates.

Here is a list of several popular SQL certifications:

• Microsoft Certified: Power BI Data Analyst Associate - Certifications
• Oracle Database Certification Paths
• PostgreSQL 13 Associate Certification | EDB

Note that these certifications usually apply to a specific database and are issued by companies responsible for developing that type of database. The level of skills required to obtain a specific certificate varies. It is usually at an intermediate to advanced level.