SQL Nukte
Every video has a Nukte page. Nukte means the key points worth remembering. You get the steps, simple examples, small animations and the real 55-table RetailMart database. Learning should be easy, so even a school pass-out can follow. Start with Get started, then go module by module.
Jo video mein bola, yahan nukte mein likha hai.
What I said in the video, written here as key points.
Get started do these once
Before Module 1: meet the database, set up your laptop, load the data, take a tour.
Part 1 · Setup
PostgreSQL, pgAdmin 4, VS Code and Git. Windows or Mac, one command or step by step.
Part 2 · Meet RetailMart
A quick overview: the retail business behind the practice database and what it contains. Databases are explained properly in Module 1.
Part 3 · Load the RetailMart dataset
Put the 55-table practice database on your laptop. Same steps on Mac and Windows.
Part 4 · Tour the database
Walk through the 16 schemas and 55 tables.
Part 5 · Website walkthrough
A complete tour of this website: the course, Nukte, the playground, the database explorer and the Setup page.
Module 1 foundations
Notes for the live class, session by session. More added as classes happen.
Session 1 · What is SQL? + Foundations
Mental models of data, Data vs Information, DBMS vs RDBMS, SQL vs NoSQL, the 80/20 rule and 52 years of database evolution.
Session 2 · How SQL is Organised — Tables, Keys & The Engine
Physical table anatomy, column types, primary & foreign keys, database hierarchy, declarative thinking & the 5 SQL command families.
Session 3 · Writing Your First Queries
Writing your first SELECT queries, scalar calculations, system introspection, the 5 psql catalog commands, schema-qualified table names, and the LIMIT safety net.
Session 4 · Data Types — Choosing the Right Type for Every Column
Why TEXT-for-everything is dangerous, core PostgreSQL types (INT, NUMERIC, TIMESTAMP, BOOLEAN), storage trade-offs, and transforming dirty schemas with ALTER TABLE ... USING.
Session 5 · Constraints — Enforcing Database Integrity
NOT NULL, DEFAULT, CHECK, UNIQUE and EXCLUDE: rules the database enforces on every write, and the error each one raises.
Session 6 · Keys — PRIMARY KEY, FOREIGN KEY & ON DELETE
One identity per row, links between tables that cannot break, what happens when a parent row is deleted, and adding keys to live tables safely.
Session 7 · DISTINCT & Filtering
WHERE, DISTINCT, IS NULL, AND/OR/NOT with brackets, LIKE/ILIKE, BETWEEN and IN on real RetailMart data.
Session 8 · Sorting & Pagination
ORDER BY with tie-breakers, NULLS FIRST/LAST, LIMIT and OFFSET pages, keyset pagination and the order PostgreSQL runs a query in.