Intermediate SQL Training

You already know how to write SQL queries. But are they fast, scalable, and production-ready?

This 2-day Intermediate SQL Training is designed for professionals who want to move beyond basic SELECT statements and start solving complex, real-world data problems with confidence. If you’ve ever struggled with multi-table joins, slow-running queries, or unclear SQL logic, this course will help you level up.

Through hands-on exercises and practical scenarios, participants will learn how to write advanced, high-performance SQL using subqueries, window functions, CTEs, and indexing strategies. You’ll also gain insight into how databases actually execute queries so you can tune performance, improve readability, and write SQL that’s not just correct, but efficient and maintainable.

By the end of the course, you’ll be equipped with the skills used by experienced SQL developers, data analysts, and BI professionals in real production environments.

Course Objectives

• Write complex SQL queries combining multiple tables.

• Use subqueries effectively (single-row, multi-row, correlated).

• Apply advanced filtering and conditional logic with CASE statements.

• Understand and use Window Functions (ROW_NUMBER, RANK, LEAD, LAG).

• Create and manage database objects (views, stored procedures, functions).

• Optimize SQL queries using indexes and execution plans.

• Work with temporary tables, table variables, and CTEs.

• Handle data manipulation using advanced techniques (MERGE, bulk insert).

• Implement best practices for writing clean, efficient, and maintainable SQL.

Prerequisites

• Completed SQL Basic Training OR equivalent experience.

• Ability to write simple SELECT queries.

• Familiarity with SELECT, WHERE, ORDER BY.

• Understanding GROUP BY and basic JOINs.

• Basic understanding of relational databases.

Course Outline

Day 1: Advanced Querying Techniques

Module 1: Review of SQL Fundamentals & Best Practices

• Review essential SQL syntax.

• Common mistakes in SQL writing.

• Query formatting standards.

• Understanding NULL behavior.

  
  

Module 2: Advanced Joins

• FULL OUTER JOIN.

• CROSS JOIN.

• SELF JOIN.

• JOIN conditions vs WHERE filters.

• Multi-table JOIN strategies.

Module 3: Subqueries & Nested Queries

• Single-value subquery.

• Multi-value subquery (IN).

• Table subqueries.

• Correlated subqueries.

• When to use subqueries vs JOINs.

Module 4: Common Table Expressions (CTEs)

• Understanding CTE structure.

• Single vs multiple CTEs.

• Recursive CTEs (intro).

• Use cases vs subqueries.

Module 5: CASE Expressions & Conditional Logic

• Syntax and rules.

• Handling multiple conditions.

• Using CASE in SELECT, WHERE, ORDER BY.