mysql - SQL比较必须确定的2个值

Question

我需要从我的表 tblResults 中找出通过次数最多的类(class)。

tblResults:
StuID       Course         Symbol
1001        CSC101         P
1001        RNG101         F
1002        CSC101         P
1002        RNF101         F
1003        HAP101         P
1004        HAP101         P

即应该给予CSC101(以及所有其他类(class)(HAP101)具有相同数量的通行证)

我已经尝试过:

CREATE VIEW Part1 AS
SELECT NumbF
FROM
  (SELECT COUNT(Course) AS NumbP,
          Course
   FROM tblResults
   WHERE Symbol = 'P')
GROUP BY Course);


CREATE VIEW Part2 AS
SELECT MAX(NumbP) AS Maxnum
FROM Part1,
     tblResults
WHERE Symbol = 'P'
GROUP BY Course;


SELECT Part1.Course
FROM Part1,
     Part2
WHERE Part1.NumbP = Part2.MaxNum

但我似乎做错了什么。请帮忙

Answer 1

这样的事情应该有效:

create view yourview as
select course, count(*) passcnt
from tblResults
where symbol = 'P'
group by course

select *
from yourview
where passcnt = (select max(passcnt) from yourview)

• SQL Fiddle Demo

请注意，您不需要该 View ，为了简单起见，我只是保留了它。