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CREATE TABLE test (`Date` DATE)
SELECT '2021-07-28' `Date` UNION ALL
SELECT '2021-07-27' UNION ALL
SELECT '2021-07-26' UNION ALL
SELECT '2021-07-25' UNION ALL
SELECT '2021-07-24' UNION ALL
SELECT '2021-07-23' UNION ALL
SELECT '2021-07-22' UNION ALL
SELECT '2021-07-21' UNION ALL
SELECT '2021-07-18' UNION ALL
SELECT '2021-07-17' UNION ALL
SELECT '2021-07-14' UNION ALL
SELECT '2021-07-11' UNION ALL
SELECT '2021-07-09' UNION ALL
SELECT '2021-07-06' UNION ALL
SELECT '2021-07-04' UNION ALL
SELECT '2021-07-03' UNION ALL
SELECT '2021-07-02';
SELECT * FROM test ORDER BY `Date`;
✓
Date
2021-07-02
2021-07-03
2021-07-04
2021-07-06
2021-07-09
2021-07-11
2021-07-14
2021-07-17
2021-07-18
2021-07-21
2021-07-22
2021-07-23
2021-07-24
2021-07-25
2021-07-26
2021-07-27
2021-07-28
…
hidden batch(es)
SELECT t1.`Date` range_start,
MIN(t2.`Date`) range_finish,
DATEDIFF(MIN(t2.`Date`), t1.`Date`) + 1 range_length
FROM test t1
JOIN test t2 ON t2.`Date` >= t1.`Date`
WHERE NOT EXISTS ( SELECT NULL
FROM test t3
WHERE t3.`Date` = t1.`Date` - INTERVAL 1 DAY )
AND NOT EXISTS ( SELECT NULL
FROM test t4
WHERE t4.`Date` = t2.`Date` + INTERVAL 1 DAY )
GROUP BY range_start
HAVING range_length > 1
ORDER BY range_start
