Поиск по совпадению сразу в трех столбцах SELECT t.mtree_id, t.parent_node, t.data FROM t_temp_table AS t INNER JOIN (SELECT t2.mtree_id, t2.parent_node, t2.data FROM t_temp_table AS t2 GROUP BY t2.mtree_id, t2.parent_node, t2.data HAVING COUNT(*)>1 ) dt ON t.mtree_id = dt.mtree_id and t.parent_node=dt.parent_node AND t.data=dt.data;
Поиск по совпадению сразу в трех столбцах
SELECT
t.mtree_id, t.parent_node, t.data
FROM t_temp_table AS t
INNER JOIN (SELECT
t2.mtree_id, t2.parent_node, t2.data
FROM t_temp_table AS t2
GROUP BY t2.mtree_id, t2.parent_node, t2.data
HAVING COUNT(*)>1
) dt ON t.mtree_id = dt.mtree_id and t.parent_node=dt.parent_node AND t.data=dt.data;