在SQL中查找两个嵌套聚合函数的最大值

Question

I have an MS Access 2007 Database with the following tables and attributes:

• Characters: Name
• Planets: Name
• TimeTable: Planet's Name, Character's Name

Time Table denotes if a character has visited a planet, there may be multiple entries for one planet.
The query I'm trying to get is this one:
For each movie, which characters visited the highest number of planets?

This is my attempt:

SELECT T.Movie, T.[Character's Name], Count(T.[Planet's Name]) AS planets
FROM TimeTable T
GROUP BY T.Movie, T.[Character's Name]
HAVING Count(T.[Planet's Name]) >= ALL (SELECT Count(T2.[Planet's Name])
FROM TimeTable T2 WHERE T.Movie = T2.Movie);

It gives me an empty result though. What is wrong with my query?

Answer 1

You have asked for the row that is greater or equal to all rows. The query below will return matches, that is, all rows with the same highest value will be returned.

SELECT t.movie,
       t.character,
       Count(t.planet) AS CountOfPlanet
FROM   timetable t
GROUP  BY t.movie, t.character
HAVING Count(t.planet) = (
   SELECT Max(countofplanet)
   FROM   (
   SELECT movie,
          [character],
          Count(planet) AS CountOfPlanet
          FROM   timetable
          GROUP  BY movie, [character]) q
   WHERE  q.movie = t.movie) 

I am afraid I could not cope with your field names. I might have overlooked the spaces, but the apostrophe's were just going too far.