<?php

use Illuminate\Support\Facades\Schema;

use Illuminate\Database\Schema\Blueprint;

use Illuminate\Database\Migrations\Migration;

class CreateStockTestTable extends Migration

{

    /**

     * Run the migrations.

     *

     * @return void

     */

    public function up()

    {

        Schema::create('stock_test', function (Blueprint $table) {

            $table->increments('id');

            $table->integer('stock')->default(0)->comment('库存1');

            $table->timestamps();

        });

    }

    /**

     * Reverse the migrations.

     *

     * @return void

     */

    public function down()

    {

        Schema::dropIfExists('stock_test');

    }

}

$model = new \App\Models\StockTest();

$id = $request->input('id',1);

try {

    // 手动开始事务

    DB::beginTransaction();

    // sql加共享锁，stock字段减1。返回成功表示成功，返回失败表示自减失败。stock字段是无符号的

    $is = DB::table('stock_test')->lockForUpdate()->increment('stock',-1);

    if($is)

    {

        log_info('id='.$id.'库存减1');

        // 提交事务

        DB::commit();

        return response('成功',200);

    }

    else

    {

        return response('失败',201);

    }

} catch (\Exception $exception) {

    // 回滚事务

    DB::rollBack();

    return response('失败',201);

}