Joins, Keys, Row Counts, and Duplicate Traps

Help learners understand this topic clearly, practice it on a small example, and produce reviewable evidence before moving to the next module.

Units

1. Unit 05.00: Joins, Keys, Row Counts, and Duplicate Traps: Read the schema and identify the grain
2. Unit 05.01: Joins, Keys, Row Counts, and Duplicate Traps: Write the query in small testable steps
3. Unit 05.02: Joins, Keys, Row Counts, and Duplicate Traps: Check row counts, joins, filters, and nulls
4. Unit 05.03: Joins, Keys, Row Counts, and Duplicate Traps: Explain what the query proves and does not prove
5. Unit 05.04: Joins, Keys, Row Counts, and Duplicate Traps: Save the final SQL evidence note

Module work

• Activity
• Knowledge check
• Summary