如果有人还在寻找答案，只要检查你的。env文件。出于某种原因，laravel创建了一个。env。示例文件，所以所有这些答案都不适合我。我修复了重命名。env的问题。.env的示例

在我将.env文件中的DB_HOST=localhost更改为DB_HOST=127.0.0.1后，它工作了

要添加到@alexventuraio的解决方案中，如果你在Laravel 5.8上遇到了这个问题，你可能想要替换数据库配置文件中'unix_socket'的值，如下:

 'mysql' => [
        'driver' => 'mysql',
        'host' => env('DB_HOST', '127.0.0.1'),
        'port' => env('DB_PORT', '3306'),
        'database' => env('DB_DATABASE', 'forge'),
        'username' => env('DB_USERNAME', 'forge'),
        'password' => env('DB_PASSWORD', ''),
        // 'unix_socket' =>'/var/run/mysqld/mysqld.sock',
        'unix_socket' => env('DB_SOCKET', ''), // replace with this line, so you can always add the mysqld.sock from the dotenv file
        'charset' => 'utf8mb4',
        'collation' => 'utf8mb4_unicode_ci',
        'prefix' => '',
        'prefix_indexes' => true,
        'strict' => false,
        'engine' => null,
        'options' => extension_loaded('pdo_mysql') ? array_filter([
            PDO::MYSQL_ATTR_SSL_CA => env('MYSQL_ATTR_SSL_CA'),
        ]) : [],
    ],

我遇到了同样的问题，我运行的是Mac OS X 10.10 Yosemite。我已经启用了操作系统自带的Apache服务器和PHP。然后，我刚刚配置了mCrypt库开始。在那之后，当我使用模型和DB时，我得到了一个错误:

[PDOException]
SQLSTATE[HY000] [2002] No such file or directory

我发现的原因只是因为PHP和MySQL不能自己连接。 为了解决这个问题，我遵循以下步骤:

Open a terminal and connect to the mysql with: mysql -u root -p It will ask you for the related password. Then once you get the mysql promt type the next command: mysql> show variables like '%sock%' You will get something like this: +-----------------------------------------+-----------------+ | Variable_name | Value | +-----------------------------------------+-----------------+ | performance_schema_max_socket_classes | 10 | | performance_schema_max_socket_instances | 322 | | socket | /tmp/mysql.sock | +-----------------------------------------+-----------------+ Keep the value of the last row: /tmp/mysql.sock In your laravel project folder, look for the database.php file there is where you configure the DB connection parameters. In the mysql section add the next line at the end: 'unix_socket' => '/tmp/mysql.sock' You must have something like this: 'mysql' => array( 'driver' => 'mysql', 'host' => 'localhost', 'database' => 'SchoolBoard', 'username' => 'root', 'password' => 'venturaa', 'charset' => 'utf8', 'collation' => 'utf8_unicode_ci', 'prefix' => '', 'unix_socket' => '/tmp/mysql.sock', ),

现在只需保存更改，并重新加载页面，它必须工作!

对于任何试图创建一个新的db连接而不是在laravel上，而是在这里寻找从终端运行PDO的答案的人。这对你有帮助。你可以重构它，使其最适合你。

<?php

class db
{
   private $DBHOST = 'localhost'; // you don't need 127.0.0.1
   private $DRIVER = 'mysql';
   private $PORT   = '8888'; // database port. 8888 is mine
   private $DB     = 'example-db';
   private $PASS   = 'example-pass';
   private $USER   = 'root';
   private $SOCKS  = ''; // can fill this or leave blank.


   // - connect (dummy connection)
   private function con()
   {
       if ($this->SOCKS == '')
       {
           // run shell command to get 
           $socks = shell_exec('netstat -ln | grep mysql');
           $socks = trim(substr($socks, strpos($socks, '/')));

           $this->SOCKS = strlen($socks) > 0 ? ';unix_socket='.$socks : '';
       }
       else
       {
          $this->SOCKS = ';unix_socket='.$this->SOCKS;
       }

       $dsn = $this->DRIVER.':host='.$this->DBHOST.';dbname='.$this->DB;

       // add socks
       $dsn .= $this->SOCKS;

       // add port
       $dsn .= (strlen($this->PORT) > 0) ? ';port='.$this->PORT : '';

       // extablish connection
       $con = new PDO($dsn, $user, $pass);

       // return PDO instance.
       return $con;
   }
   // - ends here

   // now you can call $this->con() within class to use connection 
   // would run fine on any terminal

} 

希望能有所帮助!

在我的例子中，我在我的mac终端上运行php artisan migrate，当我需要ssh进入vagrant并从那里运行它时。希望这能帮助缓解头痛。