Implements `filter(where <cond>)` for aggregate functions in LIQ queries which allows per-row conditional filtering within grouped aggregates. Also extends test suite and documentation. Signed-off-by: Matouš Jan Fialka <mjf@mjf.cz>
Implements `filter(where <cond>)` for aggregate functions in LIQ queries which allows per-row conditional filtering within grouped aggregates. Also extends test suite and documentation. Signed-off-by: Matouš Jan Fialka <mjf@mjf.cz>