Feng God taught me database, brother Wu taught me to write documents--one

Last night, Feng God said: The entity set is out of the other sets can exist alone, the contact set is associated with other sets have a meaningful

(Excerpt from Mactalk Jiangianghiang public platform)

Traditional software product development is generally the case:

1, determine the product positioning and demand, determine the scope of the first iteration.
2, the production interface prototype.
3, technology selection, and then according to the technology selection for each developer to build development environment and technology stack, such as Java environment, Python Environment, Ruby Environment, database, middleware and so on.
4, build the basic technical framework and services, including log, storage, message, cache, search, data source, cluster expansion and so on.
5. Simulate user capacity and build test environment.
6, began to write real business code, to achieve product functionality.
7, iterative development/testing, endless, round and round, until the hair fell light ...

"E to R", "two e-to-many changes two E one R":

E plus a foreign key and other links with other sets of R, which more on which side plus a foreign key to connect to the other side

Two e Many-to-many generate a contact set (PowerDesigner and Sqlworkbench are automatically generated), this contact set holds two E primary keys, and you can attach information

Feng God taught me database, brother Wu taught me to write documents--one