[英]Many to one and Many to many on same objects using datamapper ORM in Codeigniter
I have an application that requires: 我的应用程序需要:
user owns many projects. 用户拥有许多项目。 project has one owner.
项目只有一位所有者。
user works on many projects. 用户从事许多项目。 projects have many users.
项目有很多用户。
so I have 3 tables, users, projects_users, projects. 所以我有3个表,用户,projects_users,项目。 The relationships are:
关系是:
one user (owner) --- many projects (created_by) 一个用户(所有者)---许多项目(created_by)
many users (id) ---- via projects_users (user_id, project_id) ---- many projects (id). 许多用户(id)----通过projects_users(user_id,project_id)----许多项目(id)。
In Codeigniter I've set up the following relationships in the datamapper models: 在Codeigniter中,我在datamapper模型中设置了以下关系:
Class Project extends DataMapper {
var $has_one = array(
'created_by' => array(
'class' => 'user',
'other_field' => 'owns'
)
);
var $has_many = array('user' => array(
'class' => 'user',
'other_field' => 'project',
'join_table' => 'projects_users'));
and... 和...
class User extends DataMapper {
var $has_many = array(
'project' => array(
'class' => 'project',
'other_field' => 'user',
'join_table' => 'projects_users'
),
'owns' => array(
'class' => 'project',
'other_field' => 'created_by'
)
);
This doesn't seem to work however and I get a recursive error. 但是,这似乎不起作用,并且出现了递归错误。 What is the correct way to represent this relationship in datamapper?
在datamapper中表示这种关系的正确方法是什么?
Take a look at Multiple Relationships to the Same Model on the doc page: http://datamapper.wanwizard.eu/pages/advancedrelations.html 在文档页面上查看与同一模型的多重关系 : http : //datamapper.wanwizard.eu/pages/advancedrelations.html
I'm guessing something like this: 我猜是这样的:
class Project extends DataMapper {
$has_one = array(
'owner' => array(
'class' => 'user',
'other_field' => 'owned_project'
)
);
$has_many = array(
'user' => array(
'class' => 'user',
'other_field' => 'user_project'
)
);
}
class User extends DataMapper {
$has_many = array(
'owned_project' => array(
'class' => 'project',
'other_field' => 'owner'
),
'user_project' => array(
'class' => 'project',
'other_field' => 'user'
)
);
}
and you would access like this: 您将像这样访问:
$project = new Project(1); // where "1" is the ID of the project
$owner = $project->owner->get();
$project_users = $project->user->get();
// -------------------------------
$me = new User(1); // where "1" is the ID of the user
$my_projects = $me->owned_project->get();
UPDATE UPDATE
You will need to update your projects_users
join table to this: 您将需要将您的
projects_users
连接表更新为:
projects_users
--------------
user_id
owner_id
owned_project_id
user_project_id
Note that these all match the "keys" that you declared in your $has_one
and $has_many
arrays. 请注意,这些都与您在
$has_one
和$has_many
数组中声明的“键”匹配。 You will not need to update the users
or projects
tables (the only requirement is that each of them have a primary key field named "id") . 您将不需要更新
users
表或projects
表(唯一的要求是每个users
表或projects
表都有一个名为“ id”的主键字段) 。
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.