We learned some new SQL and expanded on some old friends. We learned how to update a set of rows using values from a different table. We also learned how to delete troublesome data using delete from. We touched briefly on analytical functions that we'll be using more in the next section. We got into trouble using check constraints but also learned they can help us sleep soundly at night. We had some fun using generated columns and saved ourselves some time later on by denormalizing (sort of) our table. And finally we learned about range queries using IN, a very popular way to find intersecting records.
Hope you're feeling the SQL love!