Programming

SQL to NoSQL Migration Playbook

Legacy systems are constantly being modernized. A checklist for mapping a Relational Schema (PostgreSQL) to a Document Schema (MongoDB), with a script to flatten a 3-table SQL join into a single JSON object.

Level: IntermediateProgramming

What You'll Learn

Relational vs document model trade-offs
Schema mapping checklist: SQL to MongoDB
Embedding vs referencing decisions
Handling foreign keys and joins in MongoDB
Data migration scripting with Python
Flattening a 3-table SQL join into a single JSON object
Validating migration completeness and data integrity

What's Included

🧭AI Tutor🔒

Interactive learning path with AI-generated lessons read aloud by your personal tutor

🧪Practice Lab🔒

Step-by-step lab instructions with AI guidance — run in your own IDE or sandbox.

🎙️Mock Interviews🔒

AI interviewer asks tailored questions, gives real-time feedback and a score report

📝Evaluation🔒

MCQ questions (theory, practical, code) to test your knowledge and earn a badge

⚔️Challenge AI🔒

Compete head-to-head against AI on real production problems — judged on correctness, performance, scalability, code quality, and edge cases

Course Syllabus

Module 1: Relational vs Document Thinking

  • •SQL normalisation: why it exists and its cost
  • •Document model: embedding and denormalisation
  • •When to embed vs when to reference in MongoDB
  • •Foreign key constraints vs application-level integrity
  • •Trade-off matrix: consistency, performance, flexibility

Module 2: Schema Mapping Checklist

  • •Step 1: identify access patterns before migrating
  • •Mapping one-to-one relationships
  • •Mapping one-to-many (embed array vs reference)
  • •Mapping many-to-many (junction table → dual references)
  • •Handling nullable columns and default values

Module 3: Migration Script & Validation

  • •Reading from PostgreSQL with psycopg2
  • •Flattening a 3-table join into a single JSON document
  • •Bulk-inserting into MongoDB with insert_many
  • •Row count and field-level integrity checks
  • •Capstone: migrate a User + Orders + Products schema end-to-end

You're all set

Everything in this course is unlocked.

Continue Learning →
✓AI Tutor
✓Practice Lab
✓Mock Interviews
✓Evaluation
✓Challenge AI