[5.3] Allow loading specific columns while eagerloading

[themsaid]

This allows for:

User::where(...)->with('business:id,name')->get()

Which is equivalent to:

User::where(...)->with([
  'business' => function($q){
      $q->select('id', 'name');
  }
])->get()

[shadoWalker89]

How about when we are eager loading nested relationships, and want to select columns on both the direct and distant relations ?

[themsaid]

@shadoWalker89 don't use this syntax :) Just use a closure for more advanced queries.

[kJamesy]

Might be useful to note that you have to include id in the specified columns. Therefore the following doesn't work:
User::where(...)->with('business:name')->get()

[RicardoRamirezR]

@themsaid really cool, is nice and clean.

Would it be possible having:

User::where(...)->with('business:id,name')->get()

To add some spaces:

User::where(...)->with('business: id, name')->get()

[GrahamCampbell]

I think it looks nicer without spaces tbh.

[GrahamCampbell]

Would be out of line with the rest of the framework to support spaces there I think.

[RicardoRamirezR]

I think it looks nicer with spaces

[carestad]

I am having some difficulties aliasing the primaryKey here. It does not seem to work with the closure.

Example:

MyModel::with(['relation'  => function($q) {
  $q->select('primaryId as id', 'foo as bar');
});

This will return null, while the following:

MyModel::with(['relation'  => function($q) {
  $q->select('primaryId', 'primaryId as id', 'foo as bar');
});

Will work, but will also return a primaryId key that I don't need.