SQL #2 - What is SQL [By Mosh Hamedani]

Summary

This course introduction provides an overview of databases, explaining their importance and how they are managed using Database Management Systems (DBMS). The script highlights relational databases, which organize data in linked tables using SQL, and contrasts them with non-relational (NoSQL) databases that don’t rely on tables. The course will focus on SQL for working with relational databases, specifically using MySQL. The video also addresses the different pronunciations of SQL and MySQL, with a lighthearted discussion of the historical background of these terms, setting the stage for learning SQL through MySQL in the course.

Takeaways

• 😀 A database is a collection of data stored in an easily accessible format for management and querying.
• 😀 Database Management Systems (DBMS) are software applications used to manage databases and execute instructions for querying or modifying data.
• 😀 Databases are classified into two categories: relational (SQL) and non-relational (NoSQL).
• 😀 In relational databases, data is stored in tables that are linked to each other using relationships.
• 😀 SQL (Structured Query Language) is the standard language used to query and modify data in relational databases.
• 😀 Popular relational database management systems include MySQL, SQL Server by Microsoft, and Oracle.
• 😀 While each DBMS has its own variation of SQL, all implementations are based on the standard SQL specification.
• 😀 MySQL, the most popular open-source relational database management system, will be used in this course.
• 😀 Non-relational databases do not use tables or relationships and have their own query languages, different from SQL.
• 😀 The pronunciation of SQL varies; some people pronounce it as 'SQL', while others say 'SQL'. Both are acceptable.
• 😀 MySQL is preferred by its developers to be pronounced as 'MySQL', though 'My SQL' is also acceptable.

Q & A

What is a database?

A database is a collection of data stored in a format that can be easily accessed, managed, and modified.

What is a Database Management System (DBMS)?

A DBMS is a software application used to interact with a database, allowing you to query and modify data by executing instructions and sending results back.

What are the two main categories of databases?

The two main categories of databases are relational and non-relational (NoSQL) databases.

How do relational databases organize data?

In relational databases, data is organized in tables that are linked to each other through relationships. Each table stores data about a specific type of object, such as a customer, product, or order.

What is SQL and why is it important?

SQL (Structured Query Language) is the language used to query and modify data in relational databases. It is important because it allows users to interact with and manage relational database systems effectively.

Can you name some popular relational database management systems?

Some popular relational database management systems include MySQL, SQL Server by Microsoft, and Oracle.

What makes the SQL used in different DBMS implementations similar?

Although each database management system has a slightly different implementation of SQL, they all follow the standard SQL specification, meaning that most SQL code learned in this course will work with any DBMS.

What is MySQL, and why is it used in this course?

MySQL is an open-source relational database management system that is widely used. It is chosen for this course because it is the most popular open-source database in the world.

What is the main difference between relational and non-relational databases?

Relational databases store data in tables with relationships between them and use SQL for querying, while non-relational databases do not use tables or SQL, and they have their own query languages.

How is the word SQL pronounced, and does it matter?

SQL is pronounced either as 'S-Q-L' or 'SQL', depending on who you ask. Both pronunciations are widely accepted, and there is no right or wrong way to say it.