<?php
use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;
return new class extends Migration {
 public function up(): void {
  Schema::create('readings', function (Blueprint $t) {
   $t->bigIncrements('id');
   $t->foreignId('device_id')->constrained('devices')->cascadeOnDelete();
   $t->string('metric',60);
   $t->decimal('value',10,3)->nullable();
   $t->string('value_text',50)->nullable();
   $t->timestamp('recorded_at',3);
   $t->index(['device_id','metric','recorded_at'],'idx_dmt');
   $t->index('recorded_at','idx_rec');
  });
 }
 public function down(): void { Schema::dropIfExists('readings'); }
};