Erdiagram and UML diagram

ErFigure: Entity-Contact Diagram(Entity-relation di.pdf)Used to create a data model,This is a conceptual design stage in the introduction to database systems,ErA graph provides a method to represent entities (that is, data objects), attributes, and associations. It is used to describe the conceptual model of the real world.

 

CompositionE-RThe basic elements of a graph are entities, attributes, and links. The representation is as follows:

Solid shape: indicates the entity name in a rectangle;

Attribute: It is represented by an elliptical or rounded rectangle and connected to the corresponding object with an undirected edge. The multi-value attribute is connected by two lines. The main attribute name is underlined;

Contact: It is represented by a diamond. The contact name is specified in the diamond box, and the contact type is connected to the relevant entity by the undirected edge.

InE-RThe figure must clearly indicate1Many-to-many relationship,1Pair1Relationship and many-to-many relationship.

1Pair1Link is written in the direction of two physical connections.1;

1For multiple links1Written by one party1, Write by multiple partiesN;

Multiple-to-many relationships are written in the direction of the two physical connections.N, m

 

 

 

 

 

UML:

The first use case diagram (Use Case digoal)

The second type is static digraphs, including class graphs, object graphs, and packet graphs.

The third type is the behavior diagram (behavior digraphs)

Interactive digraphs)

The fifth type is the implementation graph (Implementation divisor ).

Use case diagram: By the participants (Actor), Use cases (Use Case) And the relationship between them constitute a dynamic view used to describe system functions called the use case diagram

The Use Case chart is composed (Actor), Use cases (Use Case), System boundary, Arrow, Function composition, using the drawing method to complete

 

Flowchart: The rounded rectangle indicates start and end ". Rectangle indicates the Action Plan, common work links, and diamond indicates the problem judgment or determination (review/approval/review). parallelogram indicates the input and output, and arrow indicates the flow direction.