What is metadata? Encyclopedia is described by reference: metadata (the Metadata), also known as meta data, the relay data, is described in the data (data about data), the information description data are mainly attributes (Property) of;
It looks a bit abstract? Then we look at what specific scenario:
1, the database sysobjects, syscolumns, the configuration information is stored in tables, views, and other columns, we can check the details of these objects, a column such as the name, type, length, ...... described, we have been made to automatically generate friend code more clearly the role of them.
2, having a program highly configurable, such as custom forms, lists, etc., the information storage structure, also known as metadata, dynamic analysis shows the structure of the generated form information, there should not be done WYSIWYG familiar friends.
Above all have some idea of the application system is highly scalable applications inevitable, of course, there are many more other scenes ......
This article is to explore the importance of metadata in the application system, and how to combine the above scenario in xms, the flexible expansion and maintainability, while the liberation of our hands yards farmers ......
All along, we yards farming community project handover document, at least need to provide a database dictionary, but also to provide the required high flow chart and a description of explanation, classes and methods, etc., when it comes to documents, it is estimated we do not mind ten thousand reluctantly, write this stuff who see ah, do not want to write a, a not want to see, not to mention this system after a few hands, all people can not figure out a system logic, how to write documentation for such a large system, in fact, the more a company's specifications, as far as I understand there are 90% of people do not write do not look, look rather direct look at the code, it depends on the quality of people writing code up.
There is no way to do these two X handwritten documents? easy matter, metadata management Arise, my mother no longer have to worry about from me stay up all night to write a document, you could get back home to eat dinner! Life is short, eat on time ......
The first step: Table
Metadata first table to manage, so that we see that the table is doing with the corresponding database table which, respectively, which control the system at a glance
Step Two: Field
Details of each field of the record, various control switches, and other related properties, the demand for each item is different, the same table also there are a lot of fields personalized, here at a glance
The third step: Relationship
The relationship between each table, called the foreign key constraints in the database, through which field associates, and many, many to one, at a glance
咱们的目的是把系统做活，写死的系统有几个致命的地方：
1、简单的维护都要频繁改源码，无稳定性可言
2、客户没办法个性化，体验差
3、功能复用性低，无二次销售价值
4、难以交接，一改就乱，越改越乱
有了上面这3项的管理，后面一切扩展都轻而易举，交接时直接导出一份文档即可，省下的时间该干啥干啥去，人生苦短，你不搞python，也可以那啥啊，毕竟世界那么大
话说真有想过python再搞一套，有同样理想的咱们后续一起前进=>