Object-relational Mapping (ORM) vs SQL

What is ORM?

ORM allows developers to interact with a database using objects instead of raw SQL queries.

• Provides a layer of abstraction between database and programming language
• Represents database items (rows) as objects in the chosen language
• Attributes (columns) become properties of the object
• Enables object-oriented approach to database operations

SQL approach

SQL approach uses raw SQL queries to interact with the database.

Example:

<pre><code>import sqlite3 conn = sqlite3.connect('database.db') cursor = conn.cursor() cursor.execute("SELECT * FROM users") users = cursor.fetchall() conn.close()</code></pre>

ORM approach

ORM approach uses object-oriented syntax to interact with the database, abstracting away SQL.

Example (using Flask-SQLAlchemy):

<pre><code>from flask_sqlalchemy import SQLAlchemy db = SQLAlchemy() class User(db.Model): id = db.Column(db.Integer, primary_key=True) name = db.Column(db.String(100)) users = User.query.all()</code></pre>

Comparison of SQL and ORM

Similarities

• Both used to interact with relational databases
• Can perform CRUD operations (Create, Read, Update, Delete)
• Aim to manage data and relationships within a database system
• Both can define and enforce relationships

Differences

• ORM allows developers to use OOP, SQL uses declarative statements
• ORM abstracts SQL syntax, SQL requires writing raw queries
• ORM is language-integrated, while SQL is a standalone query language
• SQL gives more control and fine-tuning of complex queries compared to ORM

Pros and cons

Feature comparison between SQL and ORM:

• Performance: SQL is faster, ORM is slightly slower
• Complexity: SQL requires manual queries, ORM is easier with object handling
• Flexibility: SQL gives full control, ORM abstracts database logic