mssql-intersect-all.sql

# T-SQL doesn't support the INTERSECT ALL operator.
# This gets you close.
# It only returns just one copy of each duplicate.
# GROUP BY * is not valid syntax so you have to write all the column names out.
SELECT *
FROM (
  SELECT *
  FROM #HasDupes
  UNION ALL
  SELECT DISTINCT *
  FROM #HasDupes
) AS allrows
GROUP BY <all columns>
HAVING COUNT(*) > 2;