@RaceProUK Another personal preference:
SELECT F.name AS fooname
, B.quz
, sum(B.frags) AS total_frags
FROM footable F
INNER JOIN bartable B
ON B.id = F.bar_id
LEFT JOIN baztable BZ
ON BZ.bar_id = B.id
AND BZ.fizz IS NULL
WHERE F.flarg > 2
AND BZ.id IS NULL
GROUP BY F.name
, B.quz;
By placing the connectors (commas, AND
, etc.) first on the line, the query is still valid SQL if you comment out some of these lines.