Introduction to MySQL

This article is an introduction to MySQL, a database used in conjunction with web applications.

Why Use a Database?

In Module 2, you made a web site that used flatfiles to keep track of usernames and uploaded file associations. However, flatfiles are insecure, lack complex logic, and are impractical for a large-scale web application. This is where databases come in. Databases are designed from the ground up to be fast, efficient, and powerful storage solutions for any amount of data.

In CSE330, we will be using MySQL, which is a popular, open-source relational database management system for web applications.

Database Structure

A MySQL server consists of databases, each of which contains tables. Tables, in turn, consist of one or more fields (like columns), and the data is stored in one or more entries (like rows). A field in a table can be designated as an index; that is, something that can be used to look up the information in the database. The set of tables, fields, and indices in your database is called your schema.

MySQL uses the Structured Query Language (SQL) for manipulating data.

Storage Engines

MySQL is a database server, but under the hood, it actually uses a storage engine to retrieve the data. Two storage engines that are popular in the MySQL community are InnoDB and MyISAM. MyISAM is slightly faster than InnoDB, and it specializes in database schemas that involve predominantly SELECT and INSERT queries (which you will learn about later). However, MyISAM lacks InnoDB's power in making relations between tables, and MyISAM also does not support InnoDB's database transactions. Click here for more information regarding the differences between MyISAM and InnoDB.

In CSE330, we will be using InnoDB for our primary MySQL storage engine because of its support for foreign key constraints. However, in your personal applications down the road, feel free to use either InnoDB or MyISAM.