class SystemConfig extends BaseModel
{
    // 數(shù)據(jù)表名稱
    protected $name = 'system_config';
    // 當(dāng)前模型實(shí)例緩存
    private static ?SystemConfig $_instance = null;

    /**
     * 獲取當(dāng)前模型實(shí)例
     * @return SystemConfig
     */
    public static function instance(): SystemConfig
    {
        if (self::$_instance === null) self::$_instance = new self();
        return self::$_instance;
    }
}