Question

id | apples  | oranges
1    111       p
2    112       p
3    113       p
4    113       f
5    113       -
6    114       p
7    114       f
8    115       -
9    115       -
10   116       f

Looking for a way to return only the rows where:

1. oranges contains value 'f' or no value (empty)
2. there are duplicate values in apples
3. at least one duplicate in applies contains value of 'p' in oranges.

The rows 4,5 & 7 in bold and italic are what I am after.

Answer 1

You need to do a self-join. Something like this:

SELECT t1.*
FROM myTable t1
INNER JOIN myTable t2 ON t1.apples = t2.apples
WHERE t1.oranges IN ('f', '-')
AND t2.oranges = 'p'

SQL Fiddle example