What is SQL?
SQL is a standard language for accessing databases. It is used to perform operations on the records stored in the database such as updating records, deleting records, creating and modifying tables, views, etc. SQL is a server-side scripting language. It is designed for managing data in a relational database management system (RDBMS). SQL is based on relational algebra and tuple relational calculus. SQL is just a query language, it is not a database. To perform SQL queries, you need to install any database for example Oracle, MySQL, MongoDB, PostgreSQL, SQL Server, DB2, etc.
Before starting SQL, relational databases have several points that are important to keep in mind :
RDBMS:- RDBMS stands for Relational Database Management System.
Data Integrity:- Avoid data duplication
SQL Constraints:- SQL Constraints are the rules which are applied to table columns.
Better security:- Assign grant or privilege to an individual User.
Database Normalization:- It is the process to store database data very efficiently
Why SQL :
- To insert records in a database.
- To update records in a database.
- To delete records from a database.
- To retrieve data from a database.
- Create new databases, tables, and views.