Introduction to Databases

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SQL, or Structured Query Language, is a programming language used to manage and manipulate data stored in relational databases. It allows users to query, insert, update, and delete data from a database. Data, on the other hand, refers to a collection of facts represented in various forms such as words, numbers, or images. Data is a critical asset for businesses and is stored and utilized in various systems like banks, credit card companies, and online platforms.

A database serves as a repository for storing data and provides functionality for organizing and accessing it efficiently. In a relational database, data is organized into tables, resembling spreadsheets with columns and rows. Each column represents a property of the items stored in the table, while rows contain individual records or instances of those items. Relationships can be established between tables to represent connections between different sets of data.

A relational database management system (RDBMS) is a set of software tools that controls the storage, organization, and retrieval of data in a relational database. It serves as the backbone of applications across various industries such as banking, transportation, and healthcare. Examples of RDBMS include MySQL, Oracle Database, and IBM DB2.

The five basic SQL commands for interacting with a database are:

  1. CREATE TABLE: Used to create a new table in the database.
  2. INSERT: Used to add new data or records into a table.
  3. SELECT: Used to retrieve data from one or more tables based on specified criteria.
  4. UPDATE: Used to modify existing data in a table.
  5. DELETE: Used to remove data from a table based on specified conditions.

These commands form the foundation for performing CRUD (Create, Read, Update, Delete) operations on data within a relational database management system.

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