Landon Robinson shows off the HAVING clause:
Having is similar to filtering (filter(), where() or where, in a SQL clause), but the use cases differ slightly. While filtering allows you to apply conditions on your data to limit the result set, Having allows you to apply conditions on aggregate functions on your data to limit your result set.
Both limit your result set – but the difference in how they are applied is the key. In short: where filters are for row-level filtering. Having filters are for aggregate-level filtering. As a result, using a Having statement can also simplify (or outright negate) the need to use some sub-queries.
Click through for examples of HAVING in use.