Question

我有一个包含许多重复行的MySQL表。我怎样才能找到id并删除它们。我需要保留第一个lead_id并删除任何其他重复项。

因此，在此示例中，我需要找到重复的电子邮件值并删除所有行。 IE浏览器。删除lead_id为40944的所有行，并保留所有40943。

id      |   lead_id     | form  |field_number   |   value
--------+---------------+-------+---------------+----------------------
537618  |   40943       |1      | 3.3           |   Mike
537622  |   40943       |1      | 4.3           |   Mesa
537623  |   40943       |1      | 4.4           |   AZ
537624  |   40943       |1      | 4.5           |   85210
537625  |   40943       |1      | 4.6           |   United States
537626  |   40943       |1      | 5             |   mike@email.com
537627  |   40943       |1      | 6             |   (555) 555-5555
537628  |   40943       |1      | 19            |   JM-SL-I4CLR,JM-FM-I5CLR
537629  |   40943       |1      | 12            |   2015-10-01
547618  |   40944       |1      | 3.3           |   Mike
547622  |   40944       |1      | 4.3           |   Mesa
547623  |   40944       |1      | 4.4           |   AZ
547624  |   40944       |1      | 4.5           |   85210
547625  |   40944       |1      | 4.6           |   United States
547626  |   40944       |1      | 5             |   mike@email.com
547627  |   40944       |1      | 6             |   (555) 555-5555
547628  |   40944       |1      | 19            |   JM-SL-I4CLR,JM-FM-I5CLR
547629  |   40944       |1      | 12            |   2015-10-01

我试过了：

SELECT `value`, count(*) 
 FROM `lead_detail` 
 WHERE `field_number` = 5 
 GROUP BY `value` 
 HAVING count(*) > 1

结果

value          |    count(*)
---------------+------------------
mike@email.com |    2

只是不确定如何删除行？

Answer 1

你可以通过使用类似的东西来做到这一点。我自己就用过这个并且成功地完成了工作......

DELETE t1 FROM lead_detail t1, lead_detail t2 
WHERE t1.id > t2.id AND t1.field_number = t2.field_number

此外，您可以根据需要自由扩展/更改where部分（仅在需要时）。

Answer 2

这应返回您要删除的lead_id。我建议先运行它，将结果存储在临时表中并进行一些查询以确保不会丢失任何内容。即使记录混合也是如此（重复项不是潜在客户表的连续输入）

select distinct(l1.lead_id)
from lead_detail l1
inner join lead_detail l2 on  l1.value = l2.value AND l1.field_number = 5 AND l2.field_number = 5 AND l1.id != l2.id LIMIT
18446744073709551610  OFFSET 1

18446744073709551610是因为这个Can't do offset without limit

Offset跳过第一个（确保你保留一条记录）

做一个

Delete from lead_detail where lead_id in (above query)

仔细检查结果后

Answer 3

您只是在寻找重复的电子邮件，因此您可能不需要这样做。但是，当后来的线索比初始线索有更多细节时会发生什么？此查询仅供参考，如果您只想在所有字段都重复时删除。

DELETE FROM lead_detail
WHERE lead_id in
  (SELECT * FROM (SELECT lead_id FROM 
                    (SELECT lead_id,
                            GROUP_CONCAT(form ORDER BY form,field_number)as forms,
                            GROUP_CONCAT(field_number ORDER BY form,field_number) as field_numbers,
                            GROUP_CONCAT(value ORDER BY form,field_number) as `values`
                     FROM lead_detail
                     GROUP BY lead_id)l1
   WHERE EXISTS (SELECT 1 FROM 
                 (SELECT lead_id,
                            GROUP_CONCAT(form ORDER BY form,field_number)as forms,
                            GROUP_CONCAT(field_number ORDER BY form,field_number) as field_numbers,
                            GROUP_CONCAT(value ORDER BY form,field_number) as `values`
                     FROM lead_detail
                     GROUP BY lead_id)l2
                 WHERE l2.lead_id < l1.lead_id
                 AND l2.forms = l1.forms
                 AND l2.field_numbers = l1.field_numbers
                 AND l2.`values` = l1.`values`)
   )T
   )

MySQL重复具有不同id的行

3 个答案: