Feb 22: JOINS, DISTINCT, psql

Learning Objectives

After today's class, you should be able to:

• Summarize the difference between inner and outer joins.
• Explain how NULL values work in joins and aggregations.
• Use psql to run interactive commands and SQL scripts.

Lesson Outline

HW4 Debrief [5 min]

• See the Sample Solution on Canvas

Lecture Slides [30 min]

• SQL Queries: Joins

Lab Activity [20 min]

• psql – interactive terminal
• Explanation of HW5 commands

HW5 Hints [20 min]

Before leaving today, make sure you can:

• Write SQL for the first two queries on the homework
• Run the script and compare the output using meld

Your To-Do List

• Finish reading zyBook sections 3.1 – 3.4
• Finish working on Homework 5 (due Monday)