Populating Select Box based on ID - PHP - php

Question

I have two tables, schools and grades and they are many to many related. I have successfully set up the many to many relationships in the model already.
I am able to insert the select box value into the database but i having difficulty try to fetch.
When i click on a grade with id = 1 for instance, i am trying to fetch its corresponding school into the select box including the values. i get an error Integrity constraint violation: 1052 Column 'id' in field list is ambiguous.
What am i not doing right in my query?
controller
public function editPage($id)
{
$grade = Grade::whereId($id)->firstorFail();
$schools = $grade->schools()->pluck('id')->toArray();
return view('grades.edit',compact('grade','schools'));
}
Model
public function schools()
{
return $this->belongsToMany('App\School')
->withTimestamps();
}
View
<div class="form-group">
<label for="select" class="col-lg-2 control-label">School</label>
<div class="col-lg-10">
<select class="form-control" id="school" name="school[]" mulitple>
#foreach($schools as $school)
<option value="{!! $school->id !!}" #if(in_array($school->id, $schools)) selected="selected" #endif >
{!! $schools->name !!}
</option>
#endforeach
</select>
</select>
</div>
</div>

Answer 1

$school is an array in your case, so your view most likely can't decide what to do with $school->id...
Seems more likely you wanna just use school models in your view, so just only compact('grade') and then use foreach($grade->schools as $school) in your view.
Also your conditional for selected options seems wrong, every $school (which is only an id at this point, because $schools is an array of ids) is obviously in $schools because that's how your foreach is set up. But you should fix the other thing first.

Answer 2

I think it's probably because it's not sure what 'id' you want to pluck.
Try
$schools = $grade->schools()->pluck('schools.id')->toArray();
You could also just pass the grade and get the schools in the view...
public function editPage($id)
{
$grade = Grade::whereId($id)->with('schools')->firstorFail();
return view('grades.edit', compact('grade'));
}
And then
$school_options = $grade->schools->pluck('name', 'id');
#foreach($school_options->all() as $key => $value)
<option value="{{ $key }}">{{ $value }}</option>
#endforeach