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Codeigniter Datamapper多对多关系

[英]Codeigniter Datamapper many-to-many relationships

原文 2012-03-30 14:05:55 2 1 php/ codeigniter/ codeigniter-2/ codeigniter-datamapper

I'm setting up relationships in my models using DataMapper but I've hit a wall. 我正在使用DataMapper在模型中建立关系，但遇到了麻烦。

I have a RealEstate class, a Client class and a Position class which all have many to many relationships. 我有一个RealEstate类，一个Client类和一个Position类，它们都有许多对许多的关系。

Client can have the Position 'buyer' in a RealEstate Client可以在RealEstate拥有“买方” Position
Same Client can have the Position 'seller' in another RealEstate 同一Client可以在另一个RealEstate拥有Position “卖方”

So for a given RealEstate it's easy to find all the Clients s attached to it, but how can I also include what Position those clients have for the specific RealEstate ? 因此，对于给定的RealEstate可以很容易地找到与其相连的所有Clients ，但是我又如何包括这些客户在特定RealEstate所处的Position呢？

1 个解决方案

I think you have an incorrect design for it. 我认为您的设计不正确。 It really should be many-to-many relationship between Client and Position , but only one-to-many relationship between Position and RealEstate , with one on RealEstate side. Client和Position之间确实应该是多对多关系，但Position和RealEstate之间应该只有一对多关系，其中一个在RealEstate端。 It effectively emulates many-to-many relationship between RealEstate and Client that have an additional info ( Position ) in it. 它有效地模拟了RealEstate和Client之间的多对多关系，其中包含附加信息（ Position ）。

Speaking in terms of problem domain, any role ( Position ) is attached to specific RealEstate , but any Client can have arbitrary number of roles and any RealEstate can(?) have multiple roles attached to it. 就问题域而言，任何角色（ Position ）都附加到特定的RealEstate ，但是任何Client可以具有任意数量的角色，任何RealEstate可以（？）都具有多个角色。

I don't have CodeIgniter 2 at fingertips, so can't provide code samples, but let me know if you really need it - I have it CodeIgniter 2 at home. 我没有指尖的CodeIgniter 2，因此无法提供代码示例，但是请告诉我您是否真的需要-我在家中有CodeIgniter 2。