Relationships

[harikt]

Hi Paul,

I came across a strange issue in relationship. Was trying to write a unit test, but reading https://github.com/atlasphp/Atlas.Orm#relationships I got a bit confused so thought of discussing the same.

We have an articles table and users table.

Articles Table

id	user_id	title	body
1	1	something	something
2	1	another	another

Users Table

id	name
1	James
2	Bond

The mapper was defined as

class ArticleMapper extends \Atlas\Orm\Mapper\AbstractMapper
{
    protected function setRelated()
    {
        $this->manyToOne('user', UserMapper::CLASS);
        //    ->on([
        //        'user_id' => 'id'
        //    ]);
    }
}

class UserMapper extends \Atlas\Orm\Mapper\AbstractMapper
{
    protected function setRelated()
    {
        $this->oneToMany('articles', ArticleMapper::CLASS); 
        // added on later
    }
}

Now when you fetch article id 2 it returns Bond as user, but it should return James instead.

$record = $atlas->fetchRecord(ArticleMapper::CLASS, 2, ['user']);
echo $record->user->name;

When we add on it works as expected. I noticed when we change article id to 3, it tries to fetch user with id 3. Is that expected ? That is where I got confused with the docs https://github.com/atlasphp/Atlas.Orm#relationships

By default, in all relationships except many-to-one, the relationship will take the primary key column(s) in the native table, and map to those same column names in the foreign table. In the case of many-to-one, it is the reverse; that is, the relationship will take the primary key column(s) in the foreign table, and map to those same column names in the native table.

Thank you

[akDeveloper]

In your UserMapper class i see that you define oneToMany as
$this->oneToMany('user', ArticleMapper::CLASS);
Is this a typo?
I think it should be like this
$this->oneToMany('articles', ArticleMapper::CLASS);

[harikt]

@akDeveloper yes that was a typo in what I have written here not in source code.

Have updated the comment.

Thank you.

[jakejohns]

I think the issue is that it's mapping articles.id to users.id, but you want it to map articles.user_id to users.id

Docs say:

[...] same column names in the foreign table.
[...] map to those same column names in the native table.

So you gotta use the on method like you said if you want to use the terse id form for primary keys,

or you can change the db structure to use the same explicit column names if you want to use the "auto mapping" .... so like this:

article table

article_id	user_id	title	body
1	1	something	something
2	1	another	another

user table

user_id	name
1	James
2	Bond

So user_id is the name of the column in both tables.

[harikt]

@jakejohns yes. After your post, I re-read the docs once again today and sounds right.

Thank you.