The filter_having extension allows Dataset#filter, and, or and exclude to operate on the HAVING clause if the dataset already has a HAVING clause, which was the historical behavior before Sequel 4. It is only recommended to use this for backwards compatibility.
You can load this extension into specific datasets:
ds = DB[:table] ds = ds.extension(:filter_having)
Or you can load it into all of a database's datasets, which is probably the desired behavior if you are using this extension:
Related module: Sequel::FilterHaving