Data Center reconstruction-database design, data center reconstruction Database
Database Design-conceptual design stage
This phase mainly draws an erdiagram based on requirements, as shown in the following figure. The diagram shows the erdiagram based on the requirements of the data center charging system. There are 6 entities in the diagram: teachers, students, cards, basic data, bills, and computers have a one-to-many relationship and many-to-many relationship. Teachers have many different roles, but they are not subdivided here, however, in the future, we will design security mechanisms carefully. According to the conversion principle, but when we convert an ergraph into a table, a table is extracted from the many-to-many relationship, in this way, we can obtain the corresponding 10 tables in the logical design phase (the computer has only one attribute, so it is omitted ).
Database Design-Logic Design Stage
It is the table I obtained based on the ergraph (it is first represented by the class graph here, and none of the classes correspond to one table one by one ).
There are still many things to be improved in the later stage of the database. Here we will first make a simple design. Please advise on the shortcomings.