Summary

In this chapter, we learned about the incredible power of aggregate functions. We learned about several of the most common aggregate functions and how to use them. We used the GROUP BY clause and saw how it can be used to divide datasets into groups and calculate summary statistics for each group. Then, we learned how to use the HAVING clause to further filter a query. Finally, we used aggregate functions to help us clean data and analyze data quality.

We also learned about window functions. We looked at how to construct a basic window function using OVER, PARTITION BY, and ORDER BY. Then, we looked at how to calculate statistics using window functions, as well as how to adjust a window frame to calculate rolling statistics.

In the next chapter, we will look at how to import and export data in order to utilize SQL with other programs. We will use the COPY command to upload data to our database in bulk. We will also use Excel to process data from our database and then...