说帮助我有2个表:需要使用SQL查询
Person
- Id
- Name
PersonAttribute
- Id
- PersonId
- Name
- Value
而且,让我们说,每个人有2种属性(比如,性别和年龄)。样本的记录是这样的:
Person->Id = 1
Person->Name = 'John Doe'
PersonAttribute->Id = 1
PersonAttribute->PersonId = 1
PersonAttribute->Name = 'Gender'
PersonAttribute->Value = 'Male'
PersonAttribute->Id = 2
PersonAttribute->PersonId = 1
PersonAttribute->Name = 'Age'
PersonAttribute->Value = '30'
问题:我该如何查询该这样,我得到这样一个结果:
“李四”,“男”,“30”
这不能缩放以提取N个通用属性及其值。 – Timothy 2010-06-02 06:39:35