Question

CREATE TABLE IF NOT EXISTS `result` (
  `lead_id` int(11) NOT NULL AUTO_INCREMENT,
  `email` varchar(150) NOT NULL,
  `active` tinyint(1) NOT NULL DEFAULT '0',
  PRIMARY KEY (`lead_id`),
  UNIQUE KEY `lead_id` (`lead_id`),
  KEY `email` (`email`),
  KEY `active` (`active`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ;

INSERT INTO result (email, active) VALUES
('aaa@xxx.com', 1),
('aaa@xxx.com', 0),
('aaa@xxx.com', 0),
('aaa@xxx.com', 1),
('bbb@xxx.com', 1),
('bbb@xxx.com', 1),
('bbb@xxx.com', 0);


lead_id | email       | active
---------------------------
1       | aaa@xxx.com | 1
2       | aaa@xxx.com | 0
3       | aaa@xxx.com | 0
4       | aaa@xxx.com | 1
5       | bbb@xxx.com | 1
6       | bbb@xxx.com | 1
7       | bbb@xxx.com | 0

我需要更新表格，以便只有一行或任何一组匹配的电子邮件地址处于活动状态

我正在努力编写一个查询来执行此操作。哪一行无关紧要。结果看起来像这样

lead_id | email       | active
---------------------------
1       | aaa@xxx.com | 1
2       | aaa@xxx.com | 0
3       | aaa@xxx.com | 0
4       | aaa@xxx.com | 0
5       | bbb@xxx.com | 1
6       | bbb@xxx.com | 0
7       | bbb@xxx.com | 0

感谢您的建议

Answer 1

以下方法为active / 0组设置lead_id至email，该组没有最小lead_id值并且也处于活动状态。对于GROUP BY lead_id和1的{{1}}值，5子查询将使用您的示例数据创建两条记录。然后将result表连接到此表，并且不与子查询匹配的任何记录都将其active值设置为0。这没关系，因为该值已经是0，或者它是我们希望删除的副本。

UPDATE result AS r1
LEFT JOIN
(
    SELECT MIN(lead_id) AS min_lead_id, email, active
    FROM result
    WHERE active = 1
    GROUP BY email, active
) AS r2
    ON r1.lead_id = r2.min_lead_id AND r2.email = r2.email
SET r1.active = 0
WHERE r2.active IS NULL

在MySQL中更新重复记录（仅限第一个mtch）

1 个答案: