What is SQL?

SQL stands for Structured Query Language.
It is used for storing and managing data in Relational Database Management Systems (RDBMS).
It is a standard language for working with relational databases.
SQL enables users to create, read, update, and delete (CRUD) data in relational databases and tables.
All major RDBMS systems like MySQL, Informix, Oracle, MS Access, and SQL Server use SQL as their standard database language.
SQL allows users to query the database in various ways using English-like statements.

What are the Rules of SQL?

SQL follows the following rules:

Structured Query Language (SQL) is not case sensitive. However, SQL keywords are generally written in uppercase.
SQL statements are not dependent on text lines. A single SQL statement can span one or multiple lines.
Using SQL statements, you can perform most database actions, such as creating, updating, deleting, and querying data.
SQL is based on tuple relational calculus and relational algebra.

When an SQL command is executed in any Relational Database Management System (RDBMS), the system figures out the best way to carry out the request.
The SQL engine determines how to interpret and execute the task.
This process involves several components, including:
- Optimization Engine
- Query Engine
- Query Dispatcher
- Classic Query Engine, etc.
All non-SQL queries are handled by the Classic Query Engine, whereas the SQL Query Engine does not handle logical files.