c# .net 自定义新建数据库表，先判断存在不存在在新建

CREATE TABLE IF NOT EXISTS `AAAAAAAA`(
   `id` INT UNSIGNED AUTO_INCREMENT,
   `user_now` VARCHAR(100) NOT NULL,
   `user_next` VARCHAR(100) NOT NULL,
   `datetime` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
   PRIMARY KEY ( `id` )
)ENGINE=MyISAM DEFAULT CHARSET=utf8;