When building relational databases, it's crucial to comprehend the roles of primary and referential keys. A primary key acts as a distinct label for each entry in a table, ensuring accuracy and preventing repetitions. On the other hand, a referential record establishes a connection between tables, referencing the primary key in another collection.

GROUP BY is a essential SQL clause used to compile data based on common values. It allows you to explore your dataset by grouping rows with identical characteristics together. This technique is critical for revealing valuable insights from your database. Let's investigate some SQL examples to illustrate how GROUP BY can be used to execute data agg