Introduction to SQL
Learn the fundamentals of Structured Query Language using an Employee Management System database
A hands-on SQL learning cockpit with lessons, challenges, interview prep, quizzes, and tools built around real database work.
Structured learning paths for 16 roles — from Business Analyst to AI / LLM Data Engineer, plus a campus placement track for freshers — pick yours below.
Same fundamentals, different destination. Pick a track curated for how you'll actually use SQL day to day.
Reporting queries, KPI rollups, and the joins behind every dashboard.
Window functions, cohort analysis, A/B tests, and the patterns analysts live in.
Schema design, indexes, transactions, and building pipelines that hold up.
Statistics, percentiles, feature-engineering window functions, and model-ready datasets.
Constraints, indexes and execution plans, transactions, privileges, and operational SQL.
Safe CRUD, injection prevention, JOINs, transactions, and performance for real APIs.
Time-series functions, window functions, pivoting, and star-schema dashboard modeling.
Self-serve filtering, basic KPIs, safe JOINs, and the pitfalls that produce wrong numbers.
Modular SQL, star-schema marts, SCD snapshots, incremental models and tested, documented pipelines.
Profiling, source-to-target mapping checks, reconciliation and regression testing for data pipelines.
P&L rollups, fiscal calendars, YoY and YTD, budget vs actual variance and ledger tie-outs.
Funnels, cohort retention, sessions, A/B tests, segmentation and channel attribution.
Loading, JSON with VARIANT, Time Travel, performance and cost tuning, streams, tasks and security.
Text prep and chunking, vector search in SQL, RAG retrieval, LLM functions and safe text-to-SQL.
Encounters and claims data, ICD-10 cohorts, length of stay, readmissions and privacy-aware SQL.
Core queries, joins, window functions, classic placement questions and DBMS theory for freshers.
Salary ranges show average US base pay reported by Glassdoor (Aug–Oct 2026) for each role, and will vary by experience, location, company, and industry. Closest Glassdoor job titles used where needed: ETL Tester, FP&A Analyst, Snowflake Data Engineer, AI/Data Engineer, and Junior Data Analyst for Campus Placements.
Start from zero — everyone fluent in SQL began exactly here. No prior experience needed, just curiosity and ten minutes. Start with the lessons below.
Learn the fundamentals of Structured Query Language using an Employee Management System database