@ -154,7 +154,7 @@ SELECT * FROM people CROSS JOIN companies;
Do the same, but display only the rows where `people.employer_id` matches `companies.id`. Note that when you have multiple tables, you'll need to specify which table which column belongs to. Otherwise, as with the case of `id`, it could be ambiguous which table the column belongs to. When one column (such as `people.employer_id`) references the `id` column of another table, it is called a "Foreign Key".
```sql
SELECT * FROM people JOIN companies ON people.employer_id = companies.id
SELECT * FROM people JOIN companies ON people.employer_id = companies.id;
```
Do the same as the previous example, but also display any rows from the `people` that were previously left off