Vfrdtyky

I have a BuildingImage model with a OneToOne relation to BuildingType:

BuildImage Model:

/**

 * Get the source type of the Building Image.

 */

public function type()

{

    return $this->hasOne('AppBuildingType');

}

BuildingType Model:

/**

 * Get the Building Image that owns the building type.

 */

public function buildingImage()

{

    return $this->belongsTo('AppBuildingImage');

}

My tables:

building_images table -> source is the building type id

building_types table

When I try to do this in my controller just to test:
(an ImageRequest has one or more Builings and a Building has one BuildingType)

$imageRequest = ImageRequest::findOrFail($id);



$buildings = $imageRequest->buildingImages;



foreach ($buildings as $building) {

    dd($building->type);

}

I get this error:

SQLSTATE[42S22]: Column not found: 1054 Unknown column
'building_types.building_image_id' in 'where clause' (SQL: select *
from building_types where building_types.building_image_id = 45
and building_types.building_image_id is not null limit 1)

What am I doing wrong here?

Your BuildImage model should be

/**
* Get the source type of the Building Image.
*/

public function type() {

    return $this->hasOne('AppBuildingType',"id","source"); 

}

And BuildingType Model should be

/**
* Get the Building Image that owns the building type.
*/

public function buildingImage()

{

    return $this->belongsTo('AppBuildingImage',"source","id");

}

This should work.
For more info have a look
https://laravel.com/docs/5.7/eloquent-relationships#one-to-one

That's because by default laravel will look for a primary key named {model}_id, and given that you are using a different column name (source), you need to specify when defining the relationship:

As the documentation states:

Eloquent determines the foreign key of the relationship based on the model name. In this case, the Phone model is automatically assumed to have a user_id foreign key. If you wish to override this convention, you may pass a second argument to the hasOne method:

return $this->hasOne('AppPhone', 'foreign_key');

Additionally, Eloquent assumes that the foreign key should have a value matching the id (or the custom $primaryKey) column of the parent. In other words, Eloquent will look for the value of the user's id column in the user_id column of the Phone record. If you would like the relationship to use a value other than id, you may pass a third argument to the hasOne method specifying your custom key:

return $this->hasOne('AppPhone', 'foreign_key', 'local_key');

Now that that is clear. Let's talk about the relationship itself.

You are defining that a BuildImage has one BuildingType. But with that logic, the foreign key should be stored in the building_types table, and not the other way around (source column appears in the building_images table). And -I'm just assuming that- many BuildImage can belongs to an specific BuildingType. So, if this assumption is correct:

• a BuildImage belongs to a specific BuildingType.


• a BuildinType can be specify in many BuildImages

So, you should define your relationship like this:

BuildImage.php

public function type()

{

    return $this->belongsTo('AppBuildingType', 'source');

}

BuildingType.php

public function images()

{

    return $this->hasMany(BuildingImage::class, 'source');

}

Have you tried to indicate the index ID like this?

public function buildingImage()

{

    return $this->belongsTo('AppBuildingImage', 'image_request_id');

}

Eloquent determines the foreign key of the relationship based on the
model name. In this case, the Phone model is automatically assumed to
have a user_id foreign key. If you wish to override this convention,
you may pass the second argument to the hasOne method:

return $this->hasOne('AppPhone', 'foreign_key');

https://laravel.com/docs/5.7/eloquent-relationships#one-to-one