Rows disappearing despite LEFT JOIN? Verifying the difference between WHERE and ON with 3 data records

"I thought LEFT JOIN would keep the data on the left, but the number of records decreased when I added WHERE."When creating ...
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Using a LEFT OUTER JOIN vs. RIGHT OUTER JOIN in SQL

In this excerpt from SQL Queries for Mere Mortals: A Hands-On Guide to Data Manipulation in SQL, John L. Viescas and Michael J. Hernandez discuss the LEFT OUTER JOIN vs. the RIGHT OUTER JOIN and offer ...