| /*** 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'); |
|
|
