Chapter 1: “What is SQL and Databases”

In the modern world data is everywhere, the world practically revolves around data. From whenever you click a link to how long you stayed at that certain webpage, or how many steps you have walked in a certain day, that’s important data that is stored and necessary to business growth and development. Without an organized system to properly store, organize, and retrieve data efficiently then all of the data that has been collected is just useless noise. This is where the sheer importance of data bases come into play. Databases are structured systems that are designed to easily store and retrieve data.

An acronym that you will hear quite frequently in DataDays and your future career is DBMS which stands for database management system. A database management system refers to a software that allows users to interact with databases, the system handles the storage, retrieval, and updating of data. Some popular DBMS include, but not limited to: PostgreSQL (open-source and has advanced features), MySQL (popular and widely used, quick, and open-source), SQLite (serverless, and lightweight). Most databases help manage structured data which is: information organized in a predefined and consistent format, but as data sources grow more complex, we also encounter semi-structured (like JSON) and unstructured data (like images or PDFs), which require different tools like NoSQL databases.

Another term that you will hear often is Relational databases. Relational Databases store data in tables, where each table has Columns (attributes), Rows (records), Keys (identifiers that link tables together, such as a primary key or foreign key). Each table represents an entity (e.g., Students, Courses, Sales), and relationships between tables reduce redundancy and maintain data integrity.

SQL (Structured Query Language) is the standard language for interacting with relational databases. SQL lets you: Retrieve exactly the data you need, Filter, aggregate, and sort results, Join data from multiple tables, Update and insert new records, Create views for consistent data access. SQL is a declarative language which means that you describe what you want, and the DBMS figures out how to get it in an optimal way. This is different from imperative languages like Python or JavaScript, where you specify every step. In a sense this makes SQL easier to learn. SQL is used in a wide variety of applications such as: Data science: pulling data for analysis, modeling, and visualization, Software development: building apps that query or update databases, Business intelligence: dashboards, reports, KPIs, and Environmental work: tracking wildlife populations, managing restoration data.