Introduction
When retrieving data from tables in a database, it's often useful to be able to manipulate data values by using functions; to format, convert, aggregate, or otherwise affect the output from the query. Additionally, when aggregating data, you'll often want to group the results and show aggregations for each group - for example, to see total values by category.
In this module, you'll learn how to:
- Categorize built-in functions
- Use scalar functions
- Use ranking and rowset functions
- Use aggregate functions
- Summarize data with the GROUP BY clause
- Filter groups with the HAVING clause