SQL: The Complete Overview

Quick Start: SQL (Structured Query Language) is the standard language for managing and manipulating relational databases. It's been around since the 1970s and remains crucial for modern data management.

Origins and Evolution

When to Use SQL

Ideal Use Cases

Common Applications

SQL Implementations

Feature SQLite MySQL PostgreSQL SQL Server Oracle
Cost Free Free/Paid Free Paid/Free Dev Paid
Scalability Limited High Very High Very High Very High
Concurrent Users Single Multiple Multiple Multiple Multiple
Setup Complexity Minimal Moderate Moderate Complex Complex
Best For Embedded/Mobile Web Apps Complex Data Enterprise Enterprise

Popular ORMs and Tools

SQLAlchemy (Python)


from sqlalchemy import create_engine
engine = create_engine('sqlite:///database.db')

Other Popular Tools

Pros and Cons

Advantages

Limitations

Cost Considerations

Hobby Projects

Commercial Use

Alternatives

NoSQL Databases

NewSQL Databases

Glossary

ACID
Atomicity, Consistency, Isolation, Durability - properties that guarantee database transactions are processed reliably.
CRUD
Create, Read, Update, Delete - the four basic operations of persistent storage.
Foreign Key
A field that links to the primary key of another table.
Index
A data structure that improves the speed of data retrieval operations.
JOIN
A clause to combine rows from two or more tables based on a related column.
NoSQL
"Not Only SQL" - databases that provide mechanisms for storage and retrieval of data other than tabular relations.
ORM
Object-Relational Mapping - technique for converting data between incompatible type systems using object-oriented programming languages.
Primary Key
A field that uniquely identifies each row in a table.
Query
A request for data or information from a database table or combination of tables.
Schema
The structure that represents the logical view of the entire database.
Transaction
A unit of work that is performed against a database.
View
A virtual table based on the result set of an SQL statement.