SQLite Forum

Am I doing SQL wrong?
Adding to what Dan proposed and what I noted, perhaps another suggestion (which always makes it easier for me to follow) is to use the comparisons in step, meaning the Boolean test:  
(B > A) AND (B < C)
is better stated (for at least human intuition) following the mathematics notion of: [ A < B < C ]as:
(A < B) AND (B < C)

This means your CASE could be more intuitively expressed as:

  -- Testing Col1's in-the-middle-ness:
  WHEN Col2 < Col1 AND Col1 < Col3 THEN Col1 -- Note: We need 2 tests
  WHEN Col3 < Col1 AND Col1 < Col2 THEN Col1 

  -- Testing Col2's in-the-middle-ness:
  WHEN Col1 < Col2 AND Col2 < Col3 THEN Col2
  WHEN Col3 < Col2 AND Col2 < Col1 THEN Col2 

  -- Testing Col3's in-the-middle-ness:
  WHEN Col1 < Col3 AND Col3 < Col2 THEN Col3
  WHEN Col2 < Col3 AND Col3 < Col1 THEN Col3 

  ELSE -1 -- Some columns are Equal in this case.