Mastering SQL with SQL Server 2022 — Lesson 2: Joins, Aggregation, and Subqueries

Learning Objectives

• Use inner, outer, cross, and self joins
• Apply grouping, aggregates, HAVING, subqueries, common table expressions, and set operators
• Validate query results, duplicates, grain, and business definitions

Detailed Topics

• Use inner: Use inner, outer, cross, and self joins
• Apply grouping: Apply grouping, aggregates, HAVING, subqueries, common table expressions, and set operators
• Validate query results: Validate query results, duplicates, grain, and business definitions

Guided Demonstration

1. Review the requirement, users, data, dependencies, permissions, risks, and expected result.
2. Demonstrate the relevant configuration, development, administration, collaboration, analysis, or automation workflow step by step.
3. Capture settings, outputs, logs, screenshots, calculations, test results, and other useful evidence.
4. Compare the observed result with acceptance criteria and explain any corrective action.

Hands-On Activity

Create multi-table analytical SQL queries.

• Document assumptions, prerequisites, and the planned sequence before starting.
• Complete the activity and preserve evidence of normal, boundary, and failure behavior.
• Record issues, corrective actions, reusable notes, and the next improvement priority.

Scenario Analysis

• Identify the business or technical decision that must be made.
• Compare valid implementation approaches and their trade-offs.
• Consider security, privacy, accessibility, performance, support, and operational impact.

Troubleshooting Focus

• Separate symptoms from causes and collect evidence before applying a fix.
• Check configuration, data, permissions, dependencies, capacity, connectivity, and recent changes.
• Validate rollback, recovery, ownership, user impact, and business continuity.

Validation Checklist

• The requirement, scope, inputs, and expected outcome are clear.
• The selected design or configuration is documented and follows approved standards.
• Normal, boundary, failure, security, accessibility, and operational conditions are reviewed.
• The result is supported by evidence and the next improvement is prioritized.

Lesson Outcome

Learners can explain and apply Joins, Aggregation, and Subqueries in a realistic scenario and validate the result with documented evidence.