datatable.directory/app/Models/DataTable.php

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class DataTable extends Model
{
    /** Owning user */
    public function owner()
    {
        return $this->belongsTo(User::class, 'owner_id');
    }

    /** Fork precursor */
    public function precursor()
    {
        return $this->belongsTo(DataTable::class, 'precursor_id');
    }

    /** Fork descendants */
    public function descendants()
    {
        return $this->hasMany(DataTable::class, 'precursor_id');
    }

    /** Changesets */
    public function changesets()
    {
        return $this->hasMany(Changeset::class);
    }

    /** Data rows */
    public function dataRows()
    {
        return $this->hasMany(DataRow::class);
    }

    /** Changesets already merged */
    public function appliedChangesets()
    {
        return $this->hasMany(Changeset::class)->where('applied', true);
    }

    /** Changesets already merged */
    public function pendingChangesets()
    {
        return $this->hasMany(Changeset::class)->where('applied', false);
    }
}