The Structured Query Language

MySQL·2 min read·Jan 1, 2025

The Structured Query Language (SQL) is a programming language designed for managing and manipulating data held in a relational database management system, like MySQL.

It allows users to interact with the database server to perform specific tasks, like retrieving or inserting data, using a series of commands called SQL statements.

When executed, these statements are sent to the database server, which in turn interprets them, processes the data, and returns the result or confirms / invalidates the action.

The types of SQL statements

In SQL, statements can be informally classed in the following sublanguages:

  1. The data definition language (DDL) is used to define, modify, and manage database objects, such as tables, indices, and users.

  2. The data manipulation language (DML) is used to manage and manipulate data within the database.

  3. The data query language (DQL) is used to retrieve information or data from database tables based on specified criteria.

  4. The data control language (DCL) is used to ensure the security of the database and control its access by granting and revoking permissions and privileges to users.