Created
January 23, 2018 12:29
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/* get total number of followers*/ | |
SELECT PERSON_ID, COUNT(*) AS NUM_FOLLOWERS | |
FROM FOLLOWERS | |
GROUP BY PERSON_ID order by PERSON_ID asc; | |
/* test query above*/ | |
select * from FOLLOWERS where PERSON_ID =1 ORDER BY FOLLOWER_PERSON_ID ASC; | |
SELECT t1.person_id, t1.follower_person_id, t2.cnt | |
FROM followers AS t1 | |
JOIN ( | |
SELECT person_id, COUNT(*) AS cnt | |
FROM followers | |
GROUP BY person_id | |
) AS t2 ON t1.follower_person_id = t2.person_id | |
ORDER BY t1.person_id , CNT DESC; | |
SELECT t1.person_id, MAX( t2.cnt ) AS MAX_NUM_FOLLOWERS | |
FROM followers AS t1 | |
JOIN ( | |
SELECT person_id, COUNT(*) AS cnt | |
FROM followers | |
GROUP BY person_id | |
) AS t2 ON t1.follower_person_id = t2.person_id | |
GROUP BY (T1.PERSON_ID) ORDER BY t1.person_id ; | |
SELECT A.* from ( | |
SELECT t1.person_id, t1.follower_person_id, t2.cnt | |
FROM followers AS t1 | |
JOIN ( | |
SELECT person_id, COUNT(*) AS cnt | |
FROM followers | |
GROUP BY person_id | |
) AS t2 ON t1.follower_person_id = t2.person_id | |
ORDER BY t1.person_id , CNT DESC | |
) as A inner join ( | |
SELECT t1.person_id, MAX( t2.cnt ) AS MAX_NUM_FOLLOWERS | |
FROM followers AS t1 | |
JOIN ( | |
SELECT person_id, COUNT(*) AS cnt | |
FROM followers | |
GROUP BY person_id | |
) AS t2 ON t1.follower_person_id = t2.person_id | |
GROUP BY (T1.PERSON_ID) ORDER BY t1.person_id | |
) as B on A.person_id = b.person_id AND A.cnt = B.MAX_NUM_FOLLOWERS; |
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