复杂（或不可能）从mysql表中选择

Question

I have a mysql table like this:

Person     x     minutes     population
p1         F     3           p1p2p3p4
p2         B     1           p1p2p3p4
p1         B     7           p1p2p3
p3         F     2           p2p3p1
p1         F     3           p1p2
p1         B     4           p2p3p1
p2         C     3           p1p2p3
p2         B     1           p2p1p3
p2         F     7           p2p3p4
p3         B     2           p2p3p4
p1         F     3           p2p1p3p4

What I need to select, for each Person is:

1- Count the number of times x is equal to F ;

2- Count the number of times x is equal to B ;

3- Sum the value of minutes when the person appears in the variable population ;

Then, the resulting select would be like this:

Person    nF    nB    tminutes
p1        3     2     24
p2        1     2     36
p3        1     1     33

I am not sure if this is even possible. I have tried something like:

SELECT 
 Person,
 sum(x='F') as nF,
 sum(x='B') as nB,
 sum(minutes) WHERE population IS LIKE '%Person%' as tminutes
FROM myTable
GROUP BY Person

Any ideas would be very welcome! Thanks.

Answer 1

You can use the following solution, using a sub-select:

SELECT 
    Person,
    SUM(IF(x = 'F', 1, 0)) AS nF,
    SUM(IF(x = 'B', 1, 0)) AS nB,
    (SELECT SUM(minutes) FROM test_table WHERE INSTR(population, t1.Person) > 0) AS tminutes
FROM test_table t1
GROUP BY Person

The result of this query:

Person | nF | nB | tminutes
---------------------------
p1     | 3  | 2  | 27
p2     | 1  | 2  | 36
p3     | 1  | 1  | 33