Microsoft Office Visio 2003 Draw ER diagram

1. E-r graph is also called entity-Contact diagram (entities relationship Diagram), which provides methods for representing entity types, attributes, and connections to describe the conceptual model of the real world.

It is an effective method to describe the conceptual structure model of the real world. is a way of representing the conceptual model, the entity type is represented by a rectangle, the entity name is indicated in the rectangle, the attribute of the entity is represented by an ellipse, and the corresponding entity type is connected with the non-oriented edge, and the contact name is indicated in the Diamond box, and the contact names are denoted by the diamond-shaped frame, The type of contact (1:1,1:n or m:n) at the same time on the non-edge side label. 2. Composition:

There are four components in the ER diagram:

Rectangle Box: Represents the entity, and the entity name is entered in the box. Diamond Box: Indicates a contact, and the contact name is entered in the box.

Ellipse Box: A property that represents an entity or contact, and the property name is entered in the box. For the primary property name, underline it under its name.

Connections: Between entities and attributes, between entities and relationships, between contacts and attributes, and by a straight line, and by marking the type of contact on a line. (For one-to-many connections, write 1 on the two-entity connection direction;

On one side write 1, many of the parties write n; for many-to-many relationships, write n,m in the direction of two entity lines. )

First , we want to use the shape of a new mold, named er diagram, select Block Diagram, basic block diagram

Second, insert ellipse, Rectangle

Save As ER diagram

three, straight line, database orm

Four, Diamond, Basic flowchart

Next, you can start drawing the ER diagram

Click File--New--My Shape--er (new stencil)

After opening, drag the shape left-click onto the drawing page, add the corresponding entity rectangle, attribute ellipse box, entity-entity contact with straight line, one-to-many, many-to-many, multi-to-a can be added through the text tool in the outside of the line, you can directly double-click the middle of the small box, the small box automatically

The last is the problem of saving: Click on the file, save as, fill in the filename, file type can choose the normal "JPEG", but this is not editable after saving. It is recommended to save a drawing engineering file in VSD format for future revision. This is done in the ER diagram is a picture, easy to use.