in this link suggested to do not use Polymorphic Relations
for example for this Sql commands we must be without FOREIGN KEY
CREATE TABLE Comments (
comment_id SERIAL PRIMARY KEY,
comment TEXT NOT NULL,
issue_type VARCHAR(15) NOT NULL CHECK (issue_type IN (`Bugs`, `Features`)),
issue_id INT NOT NULL,
FOREIGN KEY issue_id REFERENCES ???
);
then we must be have :
CREATE TABLE Comments (
comment_id SERIAL PRIMARY KEY,
comment TEXT NOT NULL,
issue_type VARCHAR(15) NOT NULL CHECK (issue_type IN (`Bugs`, `Features`)),
issue_id INT NOT NULL,
);
this command have problem for using JOIN
or using simultaneously JOIN
s such as:
SELECT * FROM Comments c
LEFT JOIN Bugs b ON (c.issue_type = 'Bugs' AND c.issue_id = b.issue_id)
LEFT JOIN Features f ON (c.issue_type = 'Features' AND c.issue_id = f.issue_id);
those problems is only for SELECT
other problem are: UPDATE
, DELETE
whats laravel way to resolve this problems?
UPDATE: how to find post owner now?
Laravel has polymorphic relations, see here: http://laravel.com/docs/eloquent#polymorphic-relations
Your database table is setup the same (except you need to use commentable_id
and commetnable_type
to work with the following code sample), and in your models do something like this:
class Comment extends Eloquent {
public function commentable()
{
return $this->morphTo();
}
}
class Bug extends Eloquent {
public function comments()
{
return $this->morphMany('Comment', 'commentable');
}
}
class Feature extends Eloquent {
public function comments()
{
return $this->morphMany('Comments', 'commentable');
}
}
You can then use this like:
$bug = Bug::find(1)->comments();
You can also go the other way, so if you just grab a list of comments, you can then get the owner of that comment, without knowing what it is yet:
$comment = Comment::find(1);
$commentable = $comment->commentable;
// this will load the bug or feature that the comment belongs to
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