Powinno to wyglądać tak:
SELECT
id, startdate, enddate
FROM
myTable
WHERE
(startdate, enddate) IN
(
SELECT
startdate, enddate
FROM
myTable
GROUP BY
startdate, enddate
HAVING
COUNT(*) > 1
)
Powinno to wyglądać tak:
SELECT
id, startdate, enddate
FROM
myTable
WHERE
(startdate, enddate) IN
(
SELECT
startdate, enddate
FROM
myTable
GROUP BY
startdate, enddate
HAVING
COUNT(*) > 1
)