说明：  这是一款介绍数据库实现的工作流的表的建设，重在理解工作流数据库表之间的关系，为实现一个基于数据库实现的工作流，需要考虑建哪些表，如流程状态，历史日志等，以此类推，主流的工作流产品自带的系统表也就这些。基于此自己可以考虑写个状态机，实现工作流
(This is a workflow of databases to achieve the construction of the table, focusing on the workflow to understand the relationship between the database table for the realization of a workflow based on database implementation, need to consider the construction of what form, such as process status, history logs, etc. , and so on, mainstream workflow products also comes with the system tables of these. Because of this they can consider the write state machine, implement workflow)