Class 2 | Week 10 | DAT601

Today lesson is our first lesson since last Friday due to Todd being sick for the past week, thankfully he has also released the marks. I managed to barely get an A- which I think I could have done better on but from Todd's comments I can tell I didn't pay enough attention to my conceptual ER diagram.

Moving forward with the actual lecture content for today Todd is focusing on Sub Queries.

A Subquery or Inner query or a Nested query is a query within another SQL query and embedded within the WHERE clause. A subquery is used to return data that will be used in the main query as a condition to further restrict the data to be retrieved. ... A subquery cannot be immediately enclosed in a set function.
(https://www.tutorialspoint.com/sql/sql-sub-queries.htm) 18/05/2018

Subqueries can be used in a multitude of different ways, including case statements which can intelligently determine the result of the subquery.


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