You should now have a reasonable idea of how basic querying works in SQL. If you found this easy and would like an extra challenge, learn about subqueries and how they can be used (for example, subqueries can provide a different, and perhaps slightly more intuitive, way to answer the query above about scientists who have no samples). Otherwise, work on the queries and views for Assignment 2.  

In the next lab, you’ll learn how to use aggregate functions and grouping (GROUP BY) to summarise data