如何根据多个行值从 MySQL table 等数据透视表中获取不同的 id？

Question

我有一个 MySQL table 像下面这个名字 attribute_master,

现在我想获得所有 ref_id 具有 f_name = "Sam" 和 l_name = "Border".

我如何使用 MySQL 查询来做到这一点？

Answer 1

您可以使用聚合：

select ref_id
from mytable
where attr_name in ('f_name', 'l_name')
group by ref_id
having
    max(attr_name = 'f_name' and attr_value = 'Sam') = 1
    and max(attr_name = 'l_name' and attr_value = 'Border') = 1

这是另一种表达方式（假设没有重复(ref_id, attr_name)）：

select ref_id
from mytable
where (attr_name, attr_value) in (('f_name', 'Sam'), ('l_name', 'Boder'))
group by ref_id
having count(*) = 2

如何根据多个行值从 MySQL table 等数据透视表中获取不同的 id？

How to get distinct ids from a pivot like MySQL table according to multiple row values?

mysql

sql

pivot

group-by

entity-attribute-value