Php 如何在laravel 5.6中混合时检查mongo收集是否存在？

我正在我的一个项目中使用Laravel5.6、mongodb和mysql。我使用jessengers mongodb包，并通过它为我的3个集合创建了模式，尽管mongodb是无模式数据库，但出于文档目的，我创建了模式。其中一个例子是：

<?php

use Jenssegers\Mongodb\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;

class CreateChatMessagesTable extends Migration
{

    /**
     * The name of the database connection to use.
     *
     * @var string
     */
    protected $connection = 'mongodb';


    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::connection($this->connection)->create('chat_messages', function (Blueprint $table) {
            $table->increments('id');
            $table->integer('user_id');
            $table->integer('trade_id');
            $table->tinyInteger('type')->default('1');
            $table->text('content');
            $table->integer('recipient_id');
            $table->timestamp('recipient_read_at')->nullable();
            $table->timestamp('created_at')->nullable();
            $table->tinyInteger('status')->default('1');
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::connection($this->connection)
            ->table('chat_messages', function (Blueprint $collection)
            {
                $collection->drop();
            });
    }
}

---

仅在迁移文件中，但我从未尝试过这种方法，我将其保留为最后一个解决方案。请指导和帮助我。

我在搜索了拉威尔的文档后得到了解决方案

有一个方法叫做：

hasTable（）

，它返回

boolean

值来判断集合/表是否存在

我就是这样做的，现在它工作得很好：

<?php

use Jenssegers\Mongodb\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;

class CreateChatMessagesTable extends Migration
{

    /**
     * The name of the database connection to use.
     *
     * @var string
     */
    protected $connection = 'mongodb';


    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        if(Schema::connection($this->connection)->hasTable('chat_messages') == false) {
            Schema::connection($this->connection)->create('chat_messages', function (Blueprint $table) {
                $table->increments('id');
                $table->integer('user_id');
                $table->integer('trade_id');
                $table->tinyInteger('type')->default('1');
                $table->text('content');
                $table->integer('recipient_id');
                $table->timestamp('recipient_read_at')->nullable();
                $table->timestamp('created_at')->nullable();
                $table->tinyInteger('status')->default('1');
            });
        }
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        if(Schema::connection($this->connection)->hasTable('chat_messages') == false) {
            Schema::connection($this->connection)
                ->table('chat_messages', function (Blueprint $collection) {
                    $collection->drop();
                });
        }
    }
}

<?php

use Jenssegers\Mongodb\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;

class CreateChatMessagesTable extends Migration
{

    /**
     * The name of the database connection to use.
     *
     * @var string
     */
    protected $connection = 'mongodb';


    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        if(Schema::connection($this->connection)->hasTable('chat_messages') == false) {
            Schema::connection($this->connection)->create('chat_messages', function (Blueprint $table) {
                $table->increments('id');
                $table->integer('user_id');
                $table->integer('trade_id');
                $table->tinyInteger('type')->default('1');
                $table->text('content');
                $table->integer('recipient_id');
                $table->timestamp('recipient_read_at')->nullable();
                $table->timestamp('created_at')->nullable();
                $table->tinyInteger('status')->default('1');
            });
        }
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        if(Schema::connection($this->connection)->hasTable('chat_messages') == false) {
            Schema::connection($this->connection)
                ->table('chat_messages', function (Blueprint $collection) {
                    $collection->drop();
                });
        }
    }
}