Laravel查询关系

Question

I have two models: User & Tag. They have a many-to-many relation.

Table users   : id, email, password...
Table tags    : id, name...
table tag_user: id, tag_id, user_id

If can use this code to get an array with all Tags a User has:

$tagArray = User::find($user_id)->tags;

However, I can't find a quicker way to get a simple array with all the tags ids. Something like this:

$tagIdArray = array(1, 2, 3);

Answer 1

Simply use the lists method, on the tags method.

$tagIdArray = User::find($userId)->tags->lists('id');