Introduction to Database & SQL

Organized collection of data in computing.

In this unit, we will explore the basics of databases and SQL, including what they are, why they're important, and how they're used. We will also introduce some basic SQL commands.

What is a Database?

A database is an organized collection of data stored and accessed electronically. Databases are designed to offer an efficient way to store, retrieve and manipulate data. They are crucial for any system that requires persistent storage of data.

There are several types of databases, including relational databases, object-oriented databases, hierarchical databases, and network databases. The most commonly used type is the relational database, which organizes data into tables.

Understanding SQL

SQL, or Structured Query Language, is a programming language used to communicate with and manipulate databases. It is the standard language for relational database management systems, which are used in most businesses today.

SQL is used to perform tasks such as update data on a database, or retrieve data from a database. Some common relational database management systems that use SQL are Oracle, Sybase, Microsoft SQL Server, Access, Ingres, and more.

SQL is particularly important because it allows users to manipulate the data stored in a database without having to write a substantial amount of code.

SQL Basics Commands

There are several basic SQL commands that are important to understand. These include:

• SELECT: This command is used to select data from a database. The data returned is stored in a result table, called the result-set.

• INSERT INTO: This command is used to insert new data into a database.

• UPDATE: This command is used to modify the existing records in a database.

• DELETE: This command is used to delete existing records from a database.

Each of these commands plays a crucial role in interacting with a database. In the following units, we will delve deeper into these commands, as well as others, and learn how to use them effectively to manage and manipulate databases.

By understanding the basics of databases and SQL, you are now equipped with the foundational knowledge needed to delve deeper into the world of SQL. In the next unit, we will look at how to set up an SQL environment and begin executing some basic SQL commands.