SQL - Step by Step Approach to Learn SQL

 

Step by Step Learning/Practice to SQL

 

a) Pick a Database and Install on Your PC

1.       Choose one database system to start: Oracle, MySQL, PostgreSQL, Snowflake, BigQuery, or DuckDB.

2.       Install the chosen database on your computer.

 

b) Learn Basic Concepts

- Study the core SQL categories:

1.       DDL (Data Definition Language): commands like CREATE, ALTER, DROP

2.       DML (Data Manipulation Language): commands like SELECT, INSERT, UPDATE, DELETE

3.       DCL (Data Control Language): commands like GRANT, REVOKE

4.       DRL (Data Retrieval Language): typically encompassed by SELECT in many contexts (focus on how to query data)

- Note down all commands you encounter in a dedicated notebook.

 

c) Understand Concepts and Practice

- For each command category:

1.       Search for explanations and examples.

2.       Learn the syntax and typical usage.

3.       Practice by applying the command to different kinds of data (vary data types, constraints, and edge cases).

4.       Goal: complete hands-on practice for all core functions/commands you study.

 

d) Practice Problem Solving

1.       Solve problems on platforms like LeetCode, HackerRank, or others that involve SQL.

2.       Start with beginner-level problems to build confidence, then progress to intermediate/advanced datasets and queries.

3.       Track your solutions and review others’ approaches to learn different techniques.

 

e) Build a Mini Project

1.       After you have learned and practiced commands end-to-end, design a small data project.

2.       Example project ideas:

3.       A student grades and attendance tracker

4.       Implement the project end-to-end: create schema, populate data, run queries, generate reports, and possibly create simple views or stored procedures.

 

f) Doubts or Clarifications

1.       If you have doubts, discuss with friends or colleagues who have experience.

2.       Alternatively, post questions on professional networks (e.g., LinkedIn) to get feedback from peers and practitioners.

Notes

·         Use a notebook to write down commands, explanations, and solutions.

·         Do not copy-paste SQL syntax from sources; aim to understand and rephrase or recreate it from memory after practice.

·         Focus on thinking through problems and understanding concepts rather than relying on automated shortcuts.

Optional enhancements (if you have more time)

-          Create a personal cheat sheet with common commands and sample queries.

-          Build a small ETL workflow to practice loading data into your database from CSV/JSON.

-          Document learnings in a project diary: problem, approach, commands used, and outcomes.