Yii2连接PostgreSql的方法

$dev = [
 'class' => 'yiidbConnection',
 'dsn' => 'pgsql:host=122.112.182.211;port=8000;dbname=sdk_info',
 'username' => 'dbadmin',
 'password' => 'Styl2018@',
 'charset' => 'utf8',
// 'emulatePrepare' => true
];
return $dev;

class TestSdkVsent extends Base
{
 public static function getDb()
 {
 return Yii::$app->dbDws;
 }
 public static function tableName()
 {
 return 'sdk_info.tb_sdk_vsent'; // TODO: Change the autogenerated stub
 }
 public static function test()
 {
 $find = static::find();
 $result = $find->select('rtt')->limit(1) ->asArray()->one();
 return $result;
 }
}

$result = $find->select('rtt')->limit(1)->asArray()->one(); 查询到一条数据返回

$result = $find->select('rtt')->asArray()->one(); 会查询所有的数据返回一条