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/*** Division with a remainder */
SELECT DISTINCT pilot_name
FROM PilotSkills AS PS1
WHERE NOT EXISTS
(SELECT *
FROM Hangar
WHERE NOT EXISTS
(SELECT *
FROM PilotSkills AS PS2
WHERE (PS1.pilot_name = PS2.pilot_name)
AND (PS2.plane_name = Hangar.plane_name)));
/* alternatively */
SELECT PS1.pilot_name
FROM PilotSkills AS PS1, Hangar AS H1
WHERE PS1.plane_name = H1.plane_name
GROUP BY PS1.pilot_name
HAVING COUNT(PS1.plane_name) = (SELECT COUNT(plane_name) FROM Hangar);
/* Exact division */
SELECT PS1.pilot_name
FROM PilotSkills AS PS1
LEFT OUTER JOIN
Hangar AS H1
ON PS1.plane_name = H1.plane_name
GROUP BY PS1.pilot_name
HAVING COUNT(PS1.plane_name) = (SELECT COUNT(plane_name) FROM Hangar)
AND COUNT(H1.plane_name) = (SELECT COUNT(plane_name) FROM Hangar);
/* Division with JOINS */
SELECT SP1.Pilot_name
FROM (((SELECT plane_name FROM Hangar) AS H1
INNER JOIN
(SELECT pilot_name, plane_name FROM PilotSkills) AS SP1
ON H1.plane_name = SP1.plane_name)
INNER JOIN (SELECT *
FROM PilotSkills
WHERE pilot_name = 'Higgins') AS H2
ON H2.plane_name = H1.plane_name)
GROUP BY SP1.Pilot_name
HAVING COUNT(*) >= (SELECT COUNT(*)
FROM PilotSkills
WHERE pilot_name = 'Higgins');
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