首先，先来看一下问题代码：
1、控制器代码如下：
public function actionIndex()
{
$query = Country::find();
$pagination = new Pagination([
'defaultPageSize' => 5,
'totalCount' => $query->count()
]);
$countries = $query->orderBy('name')
->offset($pagination->offset)
->limit($pagination->limit)
->all();
return $this->render('index', [
'countries' => $countries,
'pagination' => $pagination,
]);
}（推荐教程：yii框架）
2、数据库配置文件db.php代码如下：
<?php
return [
'class' => 'yii\db\Connection',
'dsn' => 'mysql:host=localhost;dbname=yii2basic',
'username' => 'root',
'password' => '',
'charset' => 'utf8',
// Schema cache options (for production environment)
//'enableSchemaCache' => true,
//'schemaCacheDuration' => 60,
//'schemaCache' => 'cache',
];解决方法：
将PDO连接中的dsn的host由“localhost”改为“127.0.0.1”即可，打开文件DB.PHP，修改如下：
<?php
return [
'class' => 'yii\db\Connection',
'dsn' => 'mysql:host=127.0.0.1;dbname=yii2basic',
'username' => 'root',
'password' => '',
'charset' => 'utf8',
// Schema cache options (for production environment)
//'enableSchemaCache' => true,
//'schemaCacheDuration' => 60,
//'schemaCache' => 'cache',
];更多编程相关内容，请关注php中文网编程入门栏目！
