Original: Database Design---powerdesigner (physical model and conceptual model)
Content
First method: Conceptual model to physical model
1. First new model-select concept model (CDM)
2, the new entity (students and cards), set the corresponding properties 3, a total of four relations (1:1,1:N,N:1,N:N), according to their own needs to establish a relationship 4, establish a relationship between the entities, we can be converted into a physical model: Tools-GENERATEPDM 5, Set up the database: In the design panel blank, right-click Properties 6, build the database, set the path (Directory)-file name (F) 7, open the exported database, open the SQL (file name), execute, the database was created successfully. The second method: directly build physical model 1, select physical Model 2, build table 3, set attribute 4, set the table, Make Table Association (entity has many-to-many relationships, table can also be set)
5. Build the database and execute the created (file name-) SQL to see the newly created database.
Summarize:
basic steps in database design: Requirements Analysis-conceptual design-logical structure design-Physical structure design-database establishment and testing-database operation and maintenance.
(1) for the need to design large databases, we should follow: first draw ER model (conceptual design)-Physical design. Because the conceptual model makes it easier to see the relationships between entities, it is easy to clarify the idea. If you design the physical model directly, a bunch of foreign keys, the relationship will be messy, confusing the connection.
(2) for only a few tables of the database, we can steal lazy, but first we have to understand the relationship between, and then we directly set up a physical model to design.
Database Design---powerdesigner (physical model and conceptual model)