INTRODUCTION TO SQL
SQL, which stands for Structured Query Language, is a domain-specific language used in programming and managing relational databases. It is the standard language for interacting with and managing data in a relational database management system (RDBMS). SQL is essential for tasks such as creating and modifying database schemas, inserting, updating, and deleting data, and querying databases to retrieve information.
SQL Statements:
- SQL consists of various statements that perform specific tasks. Some common types of SQL statements include:
- Data Query Language (DQL): Used for querying data from the database. The main DQL statement is SELECT.
- Data Definition Language (DDL): Used for defining and managing the structure of the database. Examples include CREATE, ALTER, and DROP.
- Data Manipulation Language (DML): Used for manipulating data stored in the database. Examples include INSERT, UPDATE, and DELETE.
- Data Control Language (DCL): Deals with user permissions and access control. Examples include GRANT and REVOKE.
DATA TYPES IN SQL