How to get inserted row id in laravel? - laravel-5.4

Question

We created a school table with id = 56.
then We created a activity table with id = 1.
Now How to save school_id = 56 in activity table.
I have a problem. How do I get insert id from schools table?
public function store(Request $request)
{
if($request->ajax()) {
$activity = new Activity();
$activity->cluster_id = $request->cluster_id;
$activity->group_id = $request->group_id;
$activity->school_id = School::id;
$activity->save();
return response()->json(['data' => $request->all(), 'id' => $activity->school->id]);
}
}
Database
public function up()
{
Schema::create('activities', function (Blueprint $table) {
$table->increments('id');
$table->integer('school_id')->unsigned();
$table->integer('cluster_id')->unsigned();
$table->integer('group_id')->unsigned();
$table->timestamps();
$table->foreign('school_id')->references('id')->on('schools');
$table->foreign('cluster_id')->references('id')->on('clusters');
$table->foreign('group_id')->references('id')->on('groups');
});
}
Model
class Activity extends Model
{
public function school()
{
return $this->belongsTo(SchoolsList::class);
}
}

Answer 1

Suppose your School Model save method looks like this :
$school = new School;
$school->title = 'Baghoon High School';
$school->location= 'Bangladesh';
$school->save();
then you want to run this code
if($request->ajax()) {
$activity = new Activity();
$activity->school_id = $school->id;
$activity->save();
return response()->json(['data' => $request->all(), 'id' => $school->id]);
}