MySQL 8.0

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CREATE TABLE marktable (`userid` INTEGER, `activity` VARCHAR(5), `count` INTEGER);

INSERT INTO marktable (`userid`, `activity`, `count`) VALUES
  ('1', 'RoomC', '4'),
  ('2', 'RoomB', '1'),
  ('2', 'RoomB', '1'),
  ('2', 'RoomC', '1'),
  ('3', 'RoomC', '1'),
  ('3', 'RoomC', '1'),
  ('3', 'RoomC', '1'),
  ('3', 'RoomC', '1'),
  ('4', 'RoomC', '1'),
  ('4', 'RoomC', '1');
SELECT *
FROM marktable
WHERE count > 2
   OR userid IN (
     SELECT userid
     FROM marktable
     GROUP BY userid
     HAVING COUNT(*) > 2
   );


userid
activity
count


1
RoomC
4

2
RoomB
1

2
RoomB
1

2
RoomC
1

3
RoomC
1

3
RoomC
1

3
RoomC
1

3
RoomC
1


SELECT *
FROM marktable
WHERE userid IN (
  SELECT userid
  FROM marktable
  GROUP BY userid
  HAVING COUNT(*) > 2 OR MAX(count) > 2
);


userid
activity
count


1
RoomC
4

2
RoomB
1

2
RoomB
1

2
RoomC
1

3
RoomC
1

3
RoomC
1

3
RoomC
1

3
RoomC
1