SQL Basics

Structured Query Language is formed from the initial letters of SQL. It is the common query language for all databases. It emerged in the 1970s and remains popular to this day. Like modern English commands, a query language has been created to be as close as possible to the spoken language.

To procure the raw material of data, which is the basis of data science projects, it is essential to have a good understanding of the SQL language. When looking at job postings related to data, it is evident that SQL and Python are prioritized.

Fundamentally, a database, which is the raw material of data science projects, is any structure that holds data in lists in tables and rows. Databases consist of tables, columns, rows, and indexes.

Database management systems (DBMS) require resources when reading data from a database. Our computer’s resources, such as CPU and RAM, are used to analyze and query raw data. In contrast, in a database management system, we communicate with a database server. We instruct it to retrieve data using a language it understands, and the system delivers the requested data using its own resources. This database management system responds not only to us but also to many clients.

A database server is not hardware; it is software, also known as a database management system. For example, when a client computer wants to query data from a…