0608.sql (264B)
1 SELECT id, ( 2 CASE 3 WHEN T.p_id IS NULL THEN 'Root' 4 WHEN P.p_id IS NOT NULL THEN 'Inner' 5 ELSE 'Leaf' 6 END 7 ) AS type 8 FROM TREE T 9 LEFT JOIN ( 10 SELECT p_id, COUNT(*) AS count 11 FROM Tree 12 GROUP BY p_id 13 ) AS P 14 ON T.id = P.p_id