Question

我想在数据库中显示所有重复项（Example of the table here）在这种情况下，我希望：

名字（meta_key＆gt; _field_5），
姓氏（meta_key＆gt; _field_6），
电子邮件（meta_key＆gt; _field_7）

是独一无二的。因此，只显示具有这三个参数的重复项与原始参数相同。在这种情况下，它是最后两个结果（See the screenshot [Highlighted in red]）。

提前致谢！

亲切的问候，

约拿

Answer 1

我认为旋转可以帮到这里。

如果三个值有重复的话，下面的代码可以找到最早的post_id。即你称之为原始值的那个。

select min(post_id)
from (
    select post_id,
        max(case when meta_key = '_field_5' then meta_value end) as first_name,
        max(case when meta_key = '_field_6' then meta_value end) as last_name,
        max(case when meta_key = '_field_7' then meta_value end) as email
    from your_table
    where meta_key in ('_field_5', '_field_6', '_field_7')
    group by post_id
    ) t
group by first_name, last_name, email
having count(*) > 1;

您可以从群组中排除这一个以获取重复项。

select post_id,
    max(case when meta_key = '_field_5' then meta_value end) as first_name,
    max(case when meta_key = '_field_6' then meta_value end) as last_name,
    max(case when meta_key = '_field_7' then meta_value end) as email
from your_table
where meta_key in ('_field_5', '_field_6', '_field_7')
group by post_id
having post_id != (
    select min(post_id)
    from (
        select post_id,
            max(case when meta_key = '_field_5' then meta_value end) as first_name,
            max(case when meta_key = '_field_6' then meta_value end) as last_name,
            max(case when meta_key = '_field_7' then meta_value end) as email
        from your_table
        where meta_key in ('_field_5', '_field_6', '_field_7')
        group by post_id
        ) t
    group by first_name, last_name, email
    having count(*) > 1
    );

显示mysql数据库中与特定过滤器匹配的重复项

1 个答案: