插入数据是空白,求解? [ 2.0 版本 ]

INSERT INTO F_user (id) VALUES (DEFAULT)

看调试的时候,出现这个...

`
namespace app\models;

use Yii;
use yii\db\ActiveRecord;
use yii\web\IdentityInterface;

class User extends ActiveRecord implements IdentityInterface
{

public $user_id;
public $username;
public $password;
public $nickname;
public $telphone;
public $grade;
public $auth_key;
public $accessToken;

public static function tableName()
{
    return '{{%user}}';
}

/**
 * @inheritdoc
 */
public static function findIdentity($id)
{
    return static::findOne(['id' => $id]);
}

/**
 * @inheritdoc
 */
public static function findIdentityByAccessToken($token, $type = null)
{
    throw new NotSupportedException('"findIdentityByAccessToken" is not implemented.');
}

/**
 * Finds user by username
 *
 * @param string $username
 * @return static|null
 */
public static function findByUsername($username)
{
    return static::find()->where(['username' => $username]);
}

/**
 * @inheritdoc
 */
public function getId()
{
    return $this->id;
}

/**
 * @inheritdoc
 */
public function getAuthKey()
{
    return $this->auth_key;
}

/**
 * @inheritdoc
 */
public function validateAuthKey($authKey)
{
    return $this->authKey === $authKey;
}

/**
 * Validates password
 *
 * @param string $password password to validate
 * @return boolean if password provided is valid for current user
 */
public function validatePassword($password)
{
    return Yii::$app->security->validatePassword($password, $this->password);
}

/**
 * 生成 "remember me" 认证key
 */
public function generateAuthKey()
{
    $this->auth_key = Yii::$app->security->generateRandomString();
}

/**
 * 为model的password_hash字段生成密码的hash值
 *
 * @param string $password
 */
public function setPassword($password)
{
    return Yii::$app->security->generatePasswordHash($password);
}

/**
 * 用户列表
 *
 * @return $this
 */
public function view()
{
    return static::find()->Where(['is_using' => 'On']);
}

}
`

我的用户模型