What is this SQL give us

Question

I am trying to understand the SQL...Can anyone tell me what is SQL do...
SELECT *
  FROM foms.inspection_task m
WHERE type_check_code = 'P'
   AND
EXISTS (
          SELECT 0
            FROM foms.inspection_task X
           WHERE X.TRIPPLANKEY = m.TRIPPLANKEY
             AND X.dfl_sequence = m.dfl_sequence
             AND X.ROWID !=M.ROWID)

Answer 1

Hi,
SELECT *                 -- Display all columns
  FROM foms.inspection_task m     -- from this table
WHERE type_check_code = 'P'     -- with this condition
AND
EXISTS (               -- only if there's a row
          SELECT 0
            FROM foms.inspection_task X          -- in the same table
           WHERE X.TRIPPLANKEY = m.TRIPPLANKEY     -- with the same tripplankey
             AND X.dfl_sequence = m.dfl_sequence  -- and the same dfl_sequence
             AND X.ROWID !=M.ROWID)          -- but a different ROWIDROWID is unique for every row, so the effect is to pick the row "only if there's a *different* row in the same table ..."