sql求助

select count(*) from (select count(*) as uc from table group by uid having uc = 3) as t;

完成了 e1，e3，e3 ，这样算两件还是一件

算两件的话

SELECT COUNT(DISTINCT uid)
FROM (
  SELECT uid, COUNT(DISTINCT event) AS c
  FROM user_events
  GROUP BY uid
  HAVING c = 3
) as b;

算三件就不用去重

SELECT COUNT(uid) 
FROM (
  SELECT uid, COUNT(DISTINCT event) AS c
  FROM user_events
  GROUP BY uid
  HAVING c = 3
) as b;

SELECT COUNT(DISTINCT uid)  
FROM (  
  SELECT uid, COUNT(event) AS event_count  
  FROM 行为表  
  GROUP BY uid  
  HAVING COUNT(DISTINCT event) = 3  
) subquery;

分组去重

我试了一下， 楼上的回答没有问题。

DROP TABLE `test`;
CREATE TABLE `test` (
  `id` bigint(5) NOT NULL AUTO_INCREMENT,
  `uid` bigint(20) DEFAULT NULL,
  `event` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=15 DEFAULT CHARSET=utf8mb4;

INSERT INTO test (`uid`, `event`) VALUES (1, 'test_a');
INSERT INTO test (`uid`, `event`) VALUES (1, 'test_b');
INSERT INTO test (`uid`, `event`) VALUES (1, 'test_c');
INSERT INTO test (`uid`, `event`) VALUES (1, 'test_d');
INSERT INTO test (`uid`, `event`) VALUES (2, 'test_a');
INSERT INTO test (`uid`, `event`) VALUES (2, 'test_b');
INSERT INTO test (`uid`, `event`) VALUES (2, 'test_d');
INSERT INTO test (`uid`, `event`) VALUES (3, 'test_a');
INSERT INTO test (`uid`, `event`) VALUES (3, 'test_b');
INSERT INTO test (`uid`, `event`) VALUES (3, 'test_b');
INSERT INTO test (`uid`, `event`) VALUES (4, 'test_a');
INSERT INTO test (`uid`, `event`) VALUES (4, 'test_b');
INSERT INTO test (`uid`, `event`) VALUES (5, 'test_a');

SELECT COUNT(uid) as `query_a`
FROM (
  SELECT uid, COUNT(event) AS c
  FROM test
  GROUP BY uid
  HAVING c = 3
) as b;

SELECT COUNT(uid) as `query_b`
FROM (
  SELECT uid, COUNT(DISTINCT event) AS c
  FROM test
  GROUP BY uid
  HAVING c = 3
) as b;
TRUNCATE TABLE `test`;

我选择增加冗余字段，记录完成事件数或者增加表，记录每个用户每个事件完成次数，单纯靠mysql统计不大行